Training domestic dogs (Canis lupus familiaris) on a novel discrete trials odor-detection task

Dogs can be trained to reliably detect a wide variety of odors. Little scientific research, however, has been published on the rate at which dogs can learn to detect an odor, the variables influencing this rate, and how this rate may vary across dogs. In two experiments, we developed a procedure that allows the study of individual differences in the acquisition of an odor detection task in dogs. We demonstrate that differential reinforcement can be used to train a rooting response in a bin under the control of a novel odorant in discrete trials. In initial testing, we showed that as a group, twenty dogs performed significantly above chance within 24 trials, with two dogs meeting an individual criterion for above chance performance. In a follow-up experiment, we compared burying accessible food inside the target bin (with inaccessible food in the non-target bin) to the experimenter delivering food by hand following correct responses. We assessed the effect of this procedural variation on both an odor discrimination and a visual discrimination. Dogs learned faster on the odor task when the experimenter delivered food, compared to when food was placed directly in the bins. Performance on the visual task was lower than on the odor task and was unaffected by how food was delivered. Our discrete-trials procedure with experimenter-delivered food may be a useful method to study rapid acquisition of an odor-detection in dogs.     

Identifying the Lone Wolf: A Team Perspective

Increased use of sales teams reduces salespeople’s latitude to operate as “lone wolves.” A lone wolf prefers to work alone when making decisions and setting goals, has little patience for group process, sees others as less effective, and seldom values others’ ideas. Research investigating lone wolves suggests they lack organizational commitment. However, no current scale exists for identifying lone wolves. Using sales representatives and student samples, we validate a lone wolf scale and demonstrate how lone wolves differ from autonomous individuals. Having good psychometric properties, the scale is useful to practitioners for assessing representatives for sales team contexts.     

The role of forget-cue salience in list-method directed forgetting

Research suggests that manipulating the wording of the forget cue in list-method directed forgetting affects the magnitude of directed forgetting both in younger children (Aslan, Staudigl, Samenieh, & Bauml, in press) and in older adults (Sahakyan, Delaney, & Goodmon, 2008). This occurs when the forget cue overemphasises the importance of forgetting in the current context. The present experiment investigated whether de-emphasising forgetting affected the magnitude of list-method directed forgetting in college adults. Some participants received overt forget cues that explicitly instructed them to forget earlier studied items, whereas others received covert forget cues that implied forgetting by emphasising selective remembering (e.g., “you will only need to remember some of the items”). Results indicated equivalent directed forgetting for both types of cues. However, regardless of the type of cue received, participants who reported using specific forgetting strategies in response to the forget cue showed directed forgetting, whereas those that reported doing nothing did not show any effects. The results underscore that successful directed forgetting requires engagement of controlled processes.     

Reconsidering the role of temporal order in spoken word recognition

Models of spoken word recognition assume that words are represented as sequences of phonemes. We evaluated this assumption by examining phonemic anadromes, words that share the same phonemes but differ in their order (e.g., sub and bus). Using the visual-world paradigm, we found that listeners show more fixations to anadromes (e.g., sub when bus is the target) than to unrelated words (well) and to words that share the same vowel but not the same set of phonemes (sun). This contrasts with the predictions of existing models and suggests that words are not defined as strict sequences of phonemes.     

Exposure to repetitive tasks induces motor changes related to skill acquisition and inflammation in rats

The authors elucidate exposure-response relationships between repetitive tasks, inflammation, and motor changes with work-related musculoskeletal disorders. Using a rat model of reaching and handle pulling, they examined effects of performing a high-repetition, low-force (HRLF); low-repetition, high-force (LRHF); or high-repetition, high-force (HRHF) task (2 hr/day, 3 days/week, 12 weeks) on reach rate and force, percentage of successful reaches, duration of participation, and grip strength. Reach rate and reach force improved with HRLF, and percentage success increased in all groups in Week 9, and in HRLF and HRHF in Week 12, indicative of skill acquisition. Duration and grip strength showed force-dependent declines with task performance. A subset of HRHF rats received ibuprofen in Weeks 5-12. Ibuprofen significantly improved reach rate, reach force, and duration in treated rats, indicative of an inflammatory influence on reach performance. Ibuprofen improved percentage of successful reaches in Week 9, although this increase was not sustained. However, declines in grip strength, a nocifensive behavior, were not prevented by ibuprofen. Examination of cervical spinal cords of untreated and ibuprofen treated HRHF rats showed increased IL-1beta, an inflammatory cytokine, in neurons. These findings suggest that only a preventive intervention could have addressed all motor declines.     

Potentiation in young infants: The origin of the prior knowledge effect?

In two experiments with 6-month-old infants, we found that prior learning of an operant task (remembered for 2 weeks) mediated new learning of a modeling event (remembered for only 1 day) and increased its recall. Infants first learned to associate lever pressing with moving a toy train housed in a large box. One or 2 weeks later, three target actions were modeled on a hand puppet while the train box (a retrieval cue) was in view. Merely retrieving the train memory strengthened it, and simultaneously pairing its retrieved memory with the modeled actions potentiated their learning and recall. When paired 1 week later, deferred imitation increased from 1 day to 4 weeks; when paired 2 weeks later, it increased from 1 day to 6 weeks. The striking parallels between potentiated learning in infants and the prior knowledge effect in adults suggests that the prior knowledge effect originates in early infancy.     

The allure of status: high-status targets are privileged in face processing and memory

The current research tests the hypothesis that face processing is attuned to high-status faces. Across three experiments, faces of high-status targets were better recognized than faces of low-status targets. In Experiment 2, this memory advantage for high-status targets also extended to an attentional bias toward high-status targets and to stronger sociospatial memory (identity-location link) for high-status targets. Finally, Experiment 3 finds that high-status faces received more expert-style holistic processing than did low-status faces. This suggests that high-status faces also benefit more from the strategic deployment of expert face processing resources than low-status faces. Taken together, these data indicate that perceivers strategically allocate face processing resources to targets perceived to be high in status.     

The role of forget-cue salience in list-method directed forgetting

Research suggests that manipulating the wording of the forget cue in list-method directed forgetting affects the magnitude of directed forgetting both in younger children (Aslan, Staudigl, Samenieh, & Bauml, in press) and in older adults (Sahakyan, Delaney, & Goodmon, 2008). This occurs when the forget cue overemphasises the importance of forgetting in the current context. The present experiment investigated whether de-emphasising forgetting affected the magnitude of list-method directed forgetting in college adults. Some participants received overt forget cues that explicitly instructed them to forget earlier studied items, whereas others received covert forget cues that implied forgetting by emphasising selective remembering (e.g., "you will only need to remember some of the items"). Results indicated equivalent directed forgetting for both types of cues. However, regardless of the type of cue received, participants who reported using specific forgetting strategies in response to the forget cue showed directed forgetting, whereas those that reported doing nothing did not show any effects. The results underscore that successful directed forgetting requires engagement of controlled processes.     

Seeing wrath from the top (through stratified lenses): Perceivers high in social dominance orientation show superior anger identification for high-status individuals

In this research, we test the hypothesis that social status will be an orienting cue to the identification of facial expressions of emotion, particularly angry expressions, especially for those who dispositionally believe that some societal groups should dominate others (Social dominance orientation; Pratto, Sidanius, Stallworth, & Malle, 1994). Using an emotion identification task, the expression of anger was identified with greater accuracy on high-status faces than low-status faces, but only for people who endorsed rigid social hierarchies (i.e., high SDO). Furthermore, people who did not endorse social hierarchies (i.e., low SDO) did not show a preference for high-status anger. Thus, the current findings provide a novel account of how social status can be an informative cue to the expression of anger in online perceptions, especially for those who view social dominance as an important framework for society.