Recollective experience in odor recognition: Influences of adult age and familiarity

We examined recollective experience in odor memory as a function of age, intention to learn, and familiarity. Young and older adults studied a set of familiar and unfamiliar odors with incidental or intentional encoding instructions. At recognition, participants indicated whether their response was based on explicit recollection (remembering), a feeling of familiarity (knowing), or guessing. The results indicated no age-related differences in the distribution of experiential responses for unfamiliar odors. By contrast, for familiar odors the young demonstrated more explicit recollection than the older adults, who produced more know and guess responses. Intention to learn was unrelated to recollective experience. In addition, the observed age differences in remember responses for familiar odors were eliminated when odor naming was statistically controlled. This suggests that age-related deficits in activating specific odor knowledge (i.e., odor names) play an important role for age differences in recollective experience of olfactory information.     

Incidental sounds of locomotion in animal cognition

The highly synchronized formations that characterize schooling in fish and the flight of certain bird groups have frequently been explained as reducing energy expenditure. I present an alternative, or complimentary, hypothesis that synchronization of group movements may improve hearing perception. Although incidental sounds produced as a by-product of locomotion (ISOL) will be an almost constant presence to most animals, the impact on perception and cognition has been little discussed. A consequence of ISOL may be masking of critical sound signals in the surroundings. Birds in flight may generate significant noise; some produce wing beats that are readily heard on the ground at some distance from the source. Synchronization of group movements might reduce auditory masking through periods of relative silence and facilitate auditory grouping processes. Respiratory locomotor coupling and intermittent flight may be other means of reducing masking and improving hearing perception. A distinct border between ISOL and communicative signals is difficult to delineate. ISOL seems to be used by schooling fish as an aid to staying in formation and avoiding collisions. Bird and bat flocks may use ISOL in an analogous way. ISOL and interaction with animal perception, cognition, and synchronized behavior provide an interesting area for future study.     

Self-generated sounds of locomotion and ventilation and the evolution of human rhythmic abilities

It has been suggested that the basic building blocks of music mimic sounds of moving humans, and because the brain was primed to exploit such sounds, they eventually became incorporated in human culture. However, that raises further questions. Why do genetically close, culturally well-developed apes lack musical abilities? Did our switch to bipedalism influence the origins of music? Four hypotheses are raised: (1) Human locomotion and ventilation can mask critical sounds in the environment. (2) Synchronization of locomotion reduces that problem. (3) Predictable sounds of locomotion may stimulate the evolution of synchronized behavior. (4) Bipedal gait and the associated sounds of locomotion influenced the evolution of human rhythmic abilities. Theoretical models and research data suggest that noise of locomotion and ventilation may mask critical auditory information. People often synchronize steps subconsciously. Human locomotion is likely to produce more predictable sounds than those of non-human primates. Predictable locomotion sounds may have improved our capacity of entrainment to external rhythms and to feel the beat in music. A sense of rhythm could aid the brain in distinguishing among sounds arising from discrete sources and also help individuals to synchronize their movements with one another. Synchronization of group movement may improve perception by providing periods of relative silence and by facilitating auditory processing. The adaptive value of such skills to early ancestors may have been keener detection of prey or stalkers and enhanced communication. Bipedal walking may have influenced the development of entrainment in humans and thereby the evolution of rhythmic abilities.     

The Developmental Leadership Questionnaire (DLQ): some psychometric properties

The development leadership model (Larsson et al., 2003), designed to introduce refinements to the transformational leadership model, has been adopted for use in the Swedish Armed Forces. The Developmental Leadership Questionnaire (DLQ) was constructed to measure important parts of the model. The main aim of the study was to evaluate some psychometric properties of the DLQ. Most analyses are based on two subsets of individuals from a sample mostly consisting of male Swedish, military officers, each of whom has rated a given leader (n = 450 and 449 respectively). A second sample consisted of Swedish military cadets (n = 141). The dimensionality was assessed with a confirmatory factor analysis. Most DLQ scales were reasonably well reproduced and showed high or acceptable internal consistency. When related to perceived results of leadership (self-rated by leaders and rated by subordinates), results from multiple regression analyses supported what could be predicted by the theoretical model. It was concluded that the DLQ has acceptable psychometric properties and that the theoretical refinements introduced to the developmental leadership model were empirically supported.     

A Conceptual Toolkit for Intensive Early Behavioral Intervention Teachers

Intensive early behavioral intervention (IEBI) for children with autism requires effective team work involving professional therapists, parents, teachers and others. It is important for all team members to employ a common conceptual and procedural vocabulary so that communication among them is clear, unambiguous, and effective. This article outlines the rationale of a small and practical vocabulary or conceptual toolkit that we have found useful in working with teachers and families in designing, implementing, and analyzing the details of behavioral programs to help autistic children learn to speak and understand language. Special attention is given to a heuristic device called the language matrix. Illustrative data describing the course of generative language acquisition by a child with autism taught according to the language matrix approach are included.     

Both odor identification and ApoE-ε4 contribute to normative cognitive aging

Research indicates that apoliprotein E (ApoE) plays a role in the development of Alzheimer's disease (AD) and possibly in the cognitive decline associated with normative aging. More recently, researchers have shown that ApoE is expressed in olfactory brain structures, and a relationship among ApoE, AD, and olfactory function has been proposed. In the current analyses, we investigated the contribution of ApoE and odor identification in decline trajectories associated with normative cognitive aging in various domains, using longitudinal data on cognitive performance available from the Swedish Adoption/Twin Study of Aging. Data on both ApoE status and olfactory functioning were available from 455 individuals ranging in age from 50 to 88 years at the first measurement occasion. Odor identification was measured via a mailed survey. Cognitive performance was assessed in up to 5 waves of in-person testing covering a period of 16 years. Latent growth curve analyses incorporating odor identification and ApoE status indicated a main effect of odor identification on the performance level in three cognitive domains: verbal, memory, and speed. A main effect of ApoE on rates of decline after age 65 was found for verbal, spatial, and speed factors. The consistency of results across cognitive domains provides support for theories that posit central nervous system-wide origins of the olfaction-cognition-ApoE relationship; however, olfactory errors and APOE ε4 show unique and differential effects on cognitive trajectory features.     

How crucial is the response format for the testing effect?

Combining study and test trials during learning is more beneficial for long-term retention than repeated study without testing (i.e., the testing effect). Less is known about the relative efficacy of different response formats during testing. We tested the hypothesis that overt testing (typing responses on a keyboard) during a practice phase benefits later memory more than covert testing (only pressing a button to indicate successful retrieval). In Experiment 1, three groups learned 40 word pairs either by repeatedly studying them, by studying and overtly testing them, or by studying and covertly testing them. In Experiment 2, only the two testing conditions were manipulated in a within-subjects design. In both experiments, participants received cued recall tests after a short (~19 min) and a long (1 week) retention interval. In Experiment 1, all groups performed equally well at the short retention interval. The overt testing group reliably outperformed the repeated study group after 1 week, whereas the covert testing group performed insignificantly different from both these groups. Hence, the testing effect was demonstrated for overt, but failed to show for covert testing. In Experiment 2, overtly tested items were better and more quickly retrieved than those covertly tested. Further, this does not seem to be due to any differences in retrieval effort during learning. To conclude, overt testing was more beneficial for later retention than covert testing, but the effect size was small. Possible explanations are discussed.