The role of common motor responses in stimulus categorization by preschool children

The purpose of this study was to assess the role of common motor responses as the "speaker" behavior on stimulus class formation, and the emergence of functional classes. Experiment 1 examined whether training one motor response to a set of three stimuli and a second motor response to another set of three stimuli would result in correct category-sort responses for 5 typically developing preschool children. Three of the children passed the categorization tests. Experiment 2 examined whether the classes formed in Experiment 1 were functional classes, and whether participants who did not pass categorization tests in Experiment 1 would do so following common vocal tact training. The 2 participants who failed categorization tests in Experiment 1 passed these tests in Experiment 2, although none of the participants passed the tests for functional classes. The results of the current study did not unequivocally support the naming hypothesis. Future research should therefore evaluate other possible sources of control that aid in stimulus categorization.     

The role of habituation and attentional orienting in the disruption of short-term memory performance

A series of experiments explored habituation and dishabituation to repeated auditory distractors. Participants memorised lists of visually presented items in silence or while ignoring continuously presented auditory distractors. No habituation could be observed, in that the size of the auditory distractor effect did not decrease during the experiment. However, there was evidence for attentional orienting when novel auditory material was presented after a long period of repetitive stimulation, in that a change of distractors was associated with a temporary decrease in recall performance. The results are most consistent with theoretical accounts that claim that the auditory distractor effect is caused primarily by automatic interference, but that still allow attention to play a limited role in the short-term maintenance of information.     

Facet personality and surface-level diversity as team mental model antecedents: implications for implicit coordination

Team mental models (TMMs) have received much attention as important drivers of effective team processes and performance. Less is known about the factors that give rise to these shared cognitive structures. We examined potential antecedents of TMMs, with a specific focus on team composition variables, including various facets of personality and surface-level diversity. Further, we examined implicit coordination as an important outcome of TMMs. Results suggest that team composition in terms of the cooperation facet of agreeableness and racial diversity were significantly related to team-focused TMM similarity. TMM similarity was also positively predictive of implicit coordination, which mediated the relationship between TMM similarity and team performance. Post hoc analyses revealed a significant interaction between the trust facet of agreeableness and racial diversity in predicting TMM similarity. Results are discussed in terms of facilitating the emergence of TMMs and corresponding implications for team-related human resource practices.     

Resistance to extinction versus extinction as discrimination

The hypothesis that response strength might be measured by persistence of responding in the face of extinction was discredited in the 1960s because experiments showed that responding persists longer following intermittent reinforcers than following continuous reinforcers. Instead, researchers proposed that the longer persistence following intermittent reinforcers arises because intermittent reinforcement more closely resembles extinction—a discrimination theory. Attention to resistance to extinction revived because one observation seemed to support the persistence hypothesis: Following training on a multiple schedule with unequal components, responding usually persisted longer in the formerly richer component than in the formerly lean component. This observation represents an anomaly, however, because results with single schedules and concurrent schedules contradict it. We suggest that the difference in results arises because the multiple-schedule procedure, while including extensive training on stimulus discrimination, includes no training on discrimination between food available and food unavailable, whereas comparable single- and concurrent-schedule procedures include such training with repeated extinction. In Experiment 1, we replicated the original result, and in Experiment 2 showed that when the multiple-schedule procedure includes training on food/no-food discrimination, extinction following multiple schedules contradicts behavioral momentum theory and agrees with the discrimination theory and research with single and concurrent schedules.     

Interaction of Combat Exposure and Unit Cohesion in Predicting Suicide‐Related Ideation Among Post‐Deployment Soldiers

Suicide is one of the leading causes of death among U.S. Army soldiers. Suicide‐related ideation, which is associated with suicide attempts and suicide, can cause considerable distress. In a sample of 1,663 recently redeployed soldiers, we used factor analysis and structural equation modeling to test the associations between combat exposure, unit cohesion, and their interaction in predicting suicide‐related ideation. We found that combat exposure was a significant risk factor for suicide‐related ideation, while unit cohesion was a significant protective factor. The significant interaction between the two factors indicated that soldiers who experienced greater combat exposure but also had higher levels of unit cohesion had relatively lower levels of suicide‐related ideation. In addition, those who had higher levels of combat exposure and lower unit cohesion were most at risk for suicide‐related ideation. Our findings indicate the importance of unit cohesion in protecting soldiers from suicide‐related ideation and suggest a higher risk group of soldiers who should be targeted for interventions.