Understanding Aotearoa New Zealand University Students Intentions to Seek Help If Experiencing Mental Distress: A Comparison of Naturalistic and Interventional Findings.

University students globally are consistently identified as a vulnerable group for mental distress and suicide. Despite this, students report low engagement in help-seeking behaviours. This series of studies aimed to assess barriers to help-seeking for students and the impact of an intervention that sought to increase support-seeking intentions. In Study 1, 373 undergraduate psychology students completed items related to depression, anxiety, suicidal ideation, stigma, and help-seeking intentions. In Study 2, 133 undergraduate psychology students were randomly allocated into one of three intervention groups (control, infographic, video) and completed measures as used in Study 1. Despite experiencing clinically relevant symptoms and recent suicidal ideation, students in Study 1 tended to report low intentionality to seek help, citing perceptions that their distress was not serious enough or a desire to handle their issues independently. In Study 2, an infographic about different support services increased student's intentions to access support services and reduced their perception that their issues were not serious enough. Overall, Aotearoa New Zealand students endorsed similar barriers to help-seeking as students in other countries. Importantly, we demonstrated that a simple infographic intervention reduced perceptions regarding these common barriers and may increase students' knowledge about when to seek help.

The effect of MDMA on sensitivity to reinforcement rate.

Administration of (±)3,4-methylenedioxymethamphetamine (MDMA) causes memory errors by increasing proactive interference. This might occur because MDMA alters sensitivity to reinforcement. The current 2 experiments investigated this directly by assessing the acute (Experiment 1) and chronic (Experiment 2) effects of MDMA on sensitivity to reinforcement. We presented 5 pairs of concurrent variable interval schedules within each session and calculated sensitivity to reinforcement for 3 acute doses of MDMA. In contrast to the related drug, d-amphetamine, and in spite of producing reductions in response rate, MDMA did not reduce sensitivity to reinforcement rate. Chronic administration of a fixed dose of MDMA following each session reduced response rate but did not affect sensitivity to reinforcement rate. In combination with previous research, these results indicate that related drugs may have different effects on sensitivity to reinforcement and that these effects should be considered when interpreting disruptions to operant task performance caused by drug administration. (PsycINFO Database Record

The effect of opponent type on human performance in a three-alternative choice task.

Adult participants played computerised games of "Paper Scissors Rock". Participants in one group were told that they were playing against the computer, and those in the other group were told that they were playing against another participant in the adjacent room. The participant who won the most games would receive a $50 prize. For both groups however, the opponent's responses (paper, scissors, or rock) were generated by the computer, and the distribution of these responses was varied across four blocks of 126 trials. Results were analysed using the generalised matching law for the three possible pairs of alternatives (paper vs. scissors, paper vs. rock, and scissors vs. rock) across all participants in each group. Overall, significantly higher estimates of sensitivity to the distribution of opponent's responses were obtained from participants who were told their opponent was a computer compared to participants who were told their opponent was another participant. While adding to the existing literature showing that the generalised matching law is an adequate descriptor of human three-alternative choice behaviour, these findings show that external factors such as perceived opponent type can affect the efficacy of reinforcer contingencies on human behaviour. This suggests that generalising the results from tasks performed against a computer to real-life human-to-human interactions warrants some caution.

Stimulus disparity and punisher control of human signal-detection performance.

The present experiment examined the effects of varying stimulus disparity and relative punisher frequencies on signal detection by humans. Participants were placed into one of two groups. Group 3 participants were presented with 1:3 and 3:1 punisher frequency ratios, while Group 11 participants were presented with 1:11 and 11:1 punisher frequency ratios. For both groups, stimulus disparity was varied across three levels (low, medium, high) for each punisher ratio. In all conditions, correct responses were intermittently reinforced (1:1 reinforcer frequency ratio). Participants were mostly biased away from the more punished alternative, with more extreme response biases found for Group 11 participants compared to Group 3. For both groups, estimates of discriminability increased systematically across the three disparity levels and were unaffected by the punisher ratios. Likewise, estimates of response bias and sensitivity to the punisher ratios were unaffected by changes in discriminability, supporting the assumption of parameter invariance in the Davison and Tustin (1978) model of signal detection. Overall, the present experiment found no relation between stimulus control and punisher control, and provided further evidence for similar but opposite effects of punishers to reinforcers in signal-detection procedures.

Effects of point-loss punishers on human signal-detection performance.

Three experiments using human participants varied the distribution of point-gain reinforcers or point-loss punishers in two-alternative signal-detection procedures. Experiment 1 varied the distribution of point-gain reinforcers for correct responses (Group A) and point-loss punishers for errors (Group B) across conditions. Response bias varied systematically as a function of the relative reinforcer or punisher frequencies. Experiment 2 arranged two conditions - one where an unequal ratio of reinforcement (5ratio1 or 1ratio5) was presented without punishment (R-only), and another where the same reinforcer ratio was presented with an equal distribution of point-loss punishers (R+P). Response bias was significantly greater in the R-only condition than the R+P condition, supporting a subtractive model of punishment. Experiment 3 varied the distribution of point-gain reinforcers for correct responses across four unequal reinforcer ratios (5ratio1, 2ratio1, 1ratio2, 1ratio5) both without (R-only) and with (R+P) an equal distribution of point-loss punishers for errors. Response bias varied systematically with changes in relative reinforcer frequency for both R-only and R+P conditions, with 5 out of 8 participants showing increases in sensitivity estimates from R-only to R+P conditions. Overall, the results indicated that punishers have similar but opposite effects to reinforcers in detection procedures and that combined reinforcer and punisher effects might be better modeled by a subtractive punishment model than an additive punishment model, consistent with research using concurrent-schedule choice procedures.

Human performance on a two-alternative rapid-acquisition choice task.

Davison and Baum [Davison, M., Baum, W. M., 2000. Choice in a variable environment: every reinforcer counts. Journal of the Experimental Analysis of Behavior 74, 1-24.] developed a concurrent-schedule procedure where, within each session, different reinforcer ratios were arranged across components separated by brief black-outs. Behaviour adapted quickly to the reinforcer ratios and reinforcers also had local effects on responding. This procedure has been used with pigeons and rats. In the present experiment, we adapted the Davison and Baum procedure to study the effects of reinforcement on human choice behaviour. Eighteen participants were presented with four different reinforcer ratios within a single 50-minute session. Mean sensitivity to the reinforcer ratios increased within components, and preference was greater for the just-reinforced response alternative immediately following reinforcer delivery, similar to the results from non-human experiments. Although there were limitations to the current procedure, the local time scale analyses are a novel way of examining human operant behaviour.