Calculation of signal detection theory measures

Signal detection theory (SDT) may be applied to any area of psychology in which two different types of stimuli must be discriminated. We describe several of these areas and the advantages that can be realized through the application of SDT. Three of the most popular tasks used to study discriminability are then discussed, together with the measures that SDT prescribes for quantifying performance in these tasks. Mathematical formulae for the measures are presented, as are methods for calculating the measures with lookup tables, computer software specifically developed for SDT applications, and general purpose computer software (including spreadsheets and statistical analysis software).     

Inhibition of mTOR by rapamycin in the amygdala or hippocampus impairs formation and reconsolidation of inhibitory avoidance memory

Mammalian target of rapamycin (mTOR), a central regulator of protein synthesis in neurons, has been implicated in synaptic plasticity and memory. Here we show that mTOR inhibition by rapamycin in the basolateral amygdala (BLA) or dorsal hippocampus (DH) impairs both formation and reconsolidation of memory for inhibitory avoidance (IA) in rats. Male Wistar rats received bilateral infusions of vehicle or rapamycin into the BLA or DH before or after IA training or retrieval. Memory retention was tested at different time points after drug infusion. Rapamycin impaired long-term IA retention when given before or immediately after training or retrieval into the BLA. When infused into the DH, rapamycin produced memory impairment when given before training or immediately after retrieval. The impairing effects of post-retrieval rapamycin required memory retrieval and were not reversed by a reminder shock. The results provide the first evidence that mTOR in the BLA and DH might play a role in IA memory reconsolidation.     

Bursting with anxiety: adult social referencing in an interpersonal balloon analogue risk task (BART)

This study developed an interpersonal modification of the balloon analogue risk task (BART) to assess effects of a friend's real-time facial expressions on coparticipants' risk-taking. Twenty pairs of male friends and 20 pairs of female friends completed two counterbalanced versions of BART, one framed in terms of monetary gain, and the other framed in terms of avoiding loss. Each pair included a player who performed the task across both trials and a reference person in a separate cubicle connected via a soundless video link. In the suppression condition, reference persons were told to minimize facial expressions of anxiety as balloons inflated. In the expression condition, they were told to freely express anxiety. As predicted, players took greater risks and burst more balloons in the suppression condition, but only under the gain frame. Players' BART scores across both frames were also significantly negatively correlated with reference persons' scores on a questionnaire measure of dispositional expressivity (BEQ), confirming that other people's expressions can moderate one's own risk-taking.     

Predictors of treatment attendance among adolescent substance abusing runaways: a comparison of family and individual therapy modalities

This study explored and compared predictors of session attendance among substance abusing runaway adolescents and their parents using three manual‐driven interventions: ecologically‐based family therapy (EBFT), motivational enhancement therapy (MET), and the community reinforcement approach (CRA). Individual and family‐level variables, as well as time between intake and first session were used as predictors of session attendance. Adolescents (N=179) between the ages of 12–17 years old were recruited from the only runaway shelter in Columbus, Ohio. The findings showed that adolescents assigned to EBFT were more likely to attend at least one therapy session than those assigned to either CRA or MET. Fewer days between intake and the first therapy session were associated with higher family therapy attendance. Overall, individual and family factors predicted therapy attendance but these factors differed depending upon the treatment modality.     

Rural Neighborhoods and Child Aggression

Structural equation modeling with latent variables was used to evaluate the direct and mediated effects of a neighborhood risk factor (negative teen behaviors) on the parent-report aggressive behavior of 213 students in grades 3 through 5 attending a school in a low-income, rural community. Contagion and social control hypotheses were examined as well as hypotheses about whether the neighborhood served as a microsystem or exosystem for rural pre-adolescents. Analyses took into account the clustering of students and ordinal nature of the data. Findings suggest that rural neighborhoods may operate as both a microsystem and exosystem for children, with direct contagion effects on their aggressive behaviors as well as indirect social control effects through parenting practices. Direct effects on aggression were also found for parenting practices and child reports of friends’ negative behaviors. Pre-adolescence may be a transitional stage, when influences of the neighborhood on child behavior begin to compete with influences of caregivers. Findings can inform the timing and targets of violence prevention in rural communities.     

The consequences of language proficiency and difficulty of lexical access for translation performance and priming

Repetition priming was used to assess how proficiency and the ease or difficulty of lexical access influence bilingual translation. Two experiments, conducted at different universities with different Spanish–English bilingual populations and materials, showed repetition priming in word translation for same-direction and different-direction repetitions. Experiment 1, conducted in an English-dominant environment, revealed an effect of translation direction but not of direction match, whereas Experiment 2, conducted in a more balanced bilingual environment, showed an effect of direction match but not of translation direction. A combined analysis on the items common to both studies revealed that bilingual proficiency was negatively associated with response time (RT), priming, and the degree of translation asymmetry in RTs and priming. An item analysis showed that item difficulty was positively associated with RTs, priming, and the benefit of same-direction over different-direction repetition. Thus, although both participant accuracy and item accuracy are indices of learning, they have distinct effects on translation RTs and on the learning that is captured by the repetition-priming paradigm.