Child performance on discrimination tasks: Effects of amount of stimulus variation

Two independently conducted studies investigated stimulus variation effects on children's discrimination learning. The stimuli in the first study were generated by a conjunctive rule and were presented in pairs. Mean trials to criterion was significantly lower for the single-feature change treatment (17.4) than for the multiple-feature change treatment (29.9). Single-feature change-treatment transfer scores were significantly higher only for stimuli that differed in terms of one of the features. The second study not only replicated the initial finding concerning the single-feature change treatment but also found that students made more errors in reaching criterion when stimuli were generated by an exclusive disjunctive rule and were presented singly. For all tasks, the single-feature change treatment with stimuli presented in pairs was accompanied by fewer errors to criterion than the other treatments.     

CS duration,amount, and concentration effects in conditioning taste aversions

The relative contributions of the duration, amount, and concentration of a taste CS were assessed in pairings with an ionizing radiation US in two experiments. Increasing the duration of the CS (0.1% saccharin) up to 9 min yielded increasingly better conditioning over a $\text{1}\text{2}\text{-}\text{hr}$ CS-US delay interval. When the concentration of the sacharin was increased, only a few seconds' exposure to the CS was necessary for near asymptotic conditioning. It was observed that the CS duration effect had not been identified earlier because most investigators utilize 10–20 min CS access periods. The role of CS duration in conditioning over a delay was discussed with reference to the probability of the memory of the CS being present at the time of the pairing with the US event.     

Effect of CS-US pairings on shock-elicited aggression as a function of US intensity

In two experiments with paired rats, the effect of superimposing CS-US pairings on a baseline of shock-elicited aggression was studied. Baseline shocks (3.0 mA, 0.125-sec duration) occurred at a rate of 20 shocks per min throughout each session. In Experiment I, each independent group of two pairs of subjects received (in addition to baseline shocks) US shocks of 1.0, 3.0, or 5.0 mA and 5-sec duration, each shock signalled by a 1-min CS. At all three US intensities, aggression increased during the CS. In Experiment II, pairs of subjects received each unconditioned stimulus intensity in a within-subjects design. This procedure revealed a direct relationship between rate of responding and unconditioned shock intensity.     

I can see myself helping: The effect of self-awareness on prosocial behaviour

Many studies indicate that increasing self-awareness leads to individuals reflecting on their values and ideals (Silvia & Duval, 2001). This self-reflection appears to increase prosocial behaviour (Berkowitz, 1987). However, previously studies typically manipulated self-awareness in situations in which the individual may have felt pressure from the researcher to help. Thus, experimenter pressure to behave prosocially confounds the self-awareness explanation provided in past research. We used a novel experimental paradigm to manipulate self-awareness and remove the researcher's presence to decrease the likelihood that the participant would conform to experimenter demand. Participants were 36 college students (M_age = 19.52; 25 women). The results indicated a strong probability that the experimental condition participants were more prosocial than control condition participants. These findings provide additional support for the hypothesis that self-reflection increases prosocial behaviour, even without experimenter demands. These findings and the importance of studying objective self-awareness in light of the coronavirus are discussed.     

The Lived Experiences of Addiction Counselors After Marijuana Legalization

This qualitative study examines the perceptions of counselors who work with populations with addictions in states where marijuana has been legalized. Findings include themes related to client experiences, counselor experiences, specific interventions, and lack of understanding.     

Justice in epistemic gaps: The ‘proof paradox’ revisited

This paper defends the heretical view that sometimes we ought to assign legal liability based on statistical evidence alone. Recent literature focuses on potential unfairness to the defending party if we rely on bare statistics. Here, I show that capitulating in response to ‘epistemic gaps’—cases where there is a group of potential harmers but an absence of individuating evidence—can amount to a serious injustice against the party who has been harmed. Drawing on prominent civil law litigation involving pharmaceutical and industrial negligence, the overall aim is to illustrate moral pitfalls stemming from the popular idea that it is never appropriate to rely on bare statistics when settling a legal dispute.