Rediscovering the Individual in Mediation Analyses

Using the article by von Eye and colleagues as a springboard, this commentary considers a variety of challenges to valid exploration of mediation processes. Along the way, a several alternatives for reinserting the individual back into mediation processes are entertained. The configural frequency approach to mediation analyses proposed by von Eye et al. (Integrative Psychological & Behavioral Science 43(3), 2009) represents a major step toward this objective. Idiographic approaches are proposed as the next step in the progression toward individual-centered mediation analyses.

Processing of the Korean Eojoel Ambiguity

Korean writing is a syllabary where spaces occur between phrases rather than between words. This characteristic of Korean allows different types of information in Korean sentences to be dissociated in ways that are not possible in the languages that have been the focus of most psycholinguistic research, thereby providing new opportunities to investigate mechanisms of ambiguity resolution during sentence comprehension. In experiments using eye-tracking and self-paced reading, we examined how readers resolve the Eojoel ambiguity, where the grouping of syllables is ambiguous with respect to whether a phrase-final syllable is a case marker or a part of a word. This Eojoel ambiguity offers an opportunity to test how relative frequency of the lexical entries and complexity of morphological decomposition affect ambiguity resolution. Overall, the results of the experiments presented here showed that readers noticed and processed the Eojoel ambiguity very rapidly using information about the relative frequency of alternative interpretations, while the complexity of the morphological decomposition had little effect. These results are discussed in terms of constraint-based accounts (MacDonald et al. Psychol Rev 101:676–703, 1994) of ambiguity resolution.     

Interpersonal trust and organizational citizenship behavior

This study investigates the relationship between certain individual level determinants of interpersonal trust and its impact on organizational citizenship behavior. The participants (N=303) were top, middle, and lower level executives from manufacturing and services sectors. The results indicate that interaction frequency, consistency, and competence are significant predictors of interpersonal trust. Interpersonal trust is positively associated with organizational citizenship behavior, and it also partially mediated the relationship between individual level factors and organizational citizenship behavior. The results imply that the development of trust at the interpersonal level may be used as a strategy to motivate the employees to engage in extra role behaviors to ensure improved individual and organizational performance.     

Processing of Syllables in Production and Recognition Tasks

Empirical evidence for a functional role of syllables in visual word processing is abundant, however it remains rather heterogeneous. The present study aims to further specify the role of syllables and the cognitive accessibility of syllabic information in word processing. The first experiment compared performance across naming and lexical decision tasks by manipulating the number of syllables in words and non-words. Results showed a syllable number effect in both the naming task and the lexical decision task. The second experiment introduced a stimulus set consisting of isolated syllabic and non-syllabic trigrams. Syllable frequency was manipulated in a naming and in a decision task requiring participants to decide on the syllabic status of letter strings. Results showed faster responses for syllables than for non-syllables in both tasks. Syllable frequency effects were observed in the decision task. In summary, the results from these manipulations of different types of syllable information confirm an important role of syllabic units in both recognition and production.     

Stimuli inevitably generated by behavior that avoids electric shock are inherently reinforcing.

A molecular analysis based on the termination of stimuli that are positively correlated with shock and the production of stimuli that are negatively correlated with shock provides a parsimonious count for both traditional discrete-trial avoidance behavior and the data derived from more recent free-operant procedures. The necessary stimuli are provided by the intrinsic feedback generated by the subject's behavior, in addition to those presented by the experimenter. Moreover, all data compatible with the molar principle of shock-frequency reduction as reinforcement are also compatible with a delay-of-shock gradient, but some data compatible with the delay gradient are not compatible with frequency reduction. The delay gradient corresponds to functions relating magnitude of behavioral effect to the time between conditional and unconditional stimuli, the time between conditioned and primary reinforcers, and the time between responses and positive reinforcers.     

MANIPULATION OF POTENTIAL PUNISHMENT PARAMETERS IN THE TREATMENT OF SELF-INJURY1

The self-injurious behavior (SIB) of a blind, profoundly retarded male was observed within a field setting as multiple forms of punishment were applied. The effects of hair-tug punishment were first systematically examined, then hair-tug and electric shock punishment were administered in varing ratios (of punishment deliveries per SIB response) supplemented by continuous restraint contingencies and made contingent on recurrent antecedents of SIB cycles. Treatments were applied over six months of consecutive daily sessions ranging from 30 min to 8 hr duration. Posttreatment followup observations were taken 12, 24, and 34 months after treatment. Partial suppression was produced as a direct function of hair-tug punishment in the initial phase. A generally progressive decrement was produced on already lowered SIB rates with the succeeding components of the treatment package. Extended periods of total SIB suppression occurred as punishment was rendered contingent on antecedent components of each SIB response cycle. Followup observations of nearly 3 yr duration indicated total suppression generalized over all settings in which the subject functioned. The findings were related to the contrasting limits prevailing in most reports of punishment-based SIB suppression.     

Schedule-induced drinking as a function of interreinforcement interval in the rhesus monkey

Lever presses by two rhesus monkeys produced food pellets that were assigned by both an ascending and descending series of fixed-interval schedules whose values varied between 1 and 512 sec. The amount of schedule-induced drinking was bitonically related to interreinforcement interval, reaching a maximum at approximately 120 sec and declining at longer fixed intervals. The relation between water intake and interreinforcement interval was complexly related to two drinking measures: (1) the probability of drinking following a pellet and (2) the amount drunk per bout. Drinking rate was also bitonically related to interreinforcement interval.     

Effects on responding of mixed and multiple schedules of signalled and unsignalled response-dependent electric-shock delivery

Responding in two rats was maintained under mixed and multiple variable-interval 35-sec variable-interval 35-sec food delivery schedules. Similar rates and patterns of responding occurred in each component of the two schedules. Mixed and multiple variable-interval 65-sec variable-interval 65-sec schedules of response-dependent shock delivery were super-imposed on the mixed and multiple baseline food schedules, respectively. In one component, a 5-sec stimulus was presented on the average of once every 65 sec. Offset of the stimulus arranged that the next response would produce shock. In the other component, no stimulus was presented during the 5-sec period. The mixed schedule of signalled and unsignalled dependent shock delivery yielded similar degrees of response suppression in each component, but the multiple schedule of shock delivery revealed differential degrees of response suppression. Considerably more suppression occurred in the component not associated with the preshock stimulus, thus implicating the discriminative functions of the correlated stimulus.     

Choice and foraging: the effects of accessibility on acceptability.

Pigeons responded in a successive-encounters choice procedure in which accessibility of the less profitable of two outcomes varied either in terms of probability of encounter or search time to encounter (keeping search time to the more profitable outcome constant). When the less profitable outcome was made more probable its acceptance became more likely. However, when search time to encounter the less profitable outcome was shortened, its acceptance became less likely. Both results are consistent with the delay-reduction hypothesis and with an optimality model developed for application to the successive-encounters choice procedure.