Long-term maintenance of immediate or delayed extinction is determined by the extinction-test interval

Short acquisition-extinction intervals (immediate extinction) can lead to either more or less spontaneous recovery than long acquisition-extinction intervals (delayed extinction). Using rat subjects, we observed less spontaneous recovery following immediate than delayed extinction (Experiment 1). However, this was the case only if a relatively long extinction-test interval was used; a relatively short extinction-test interval yielded the opposite result (Experiment 2). Previous data appear consistent with this observation suggesting that, although delayed extinction appears more beneficial in the short term, immediate extinction may have more favorable long-term effects. These observations may have important implications for attenuation of relapse in clinical situations.     

Age-related differences in postural reaction time and coordination during voluntary sway movements

The elderly are known to exhibit declines in postural control during standing and walking, however little is known about how the elderly react under time-critical and challenging postural situations. The purpose of this study was to examine age-related differences in reaction time (RT) and the pattern of temporal coordination between center of pressure (COP), trunk and head motion during voluntary postural sway movements. Healthy young (n=10; mean=24 years; SD=5 years) and elderly men (n=8; mean=75 years; SD=2 years) stood on a force plate with tri-axial accelerometers attached to the head and lower trunk. Participants were required to generate sway in the anterior-posterior (AP) or medial-lateral (ML) direction in response to an auditory cue during two different testing conditions called Static reaction and Dynamic reaction. Static reactions involved the initiation of voluntary sway in either the AP or ML direction from quiet stance. Dynamic reactions involved an orthogonal switch of voluntary sway between the AP and ML directions. Compared to the young, elderly individuals exhibited slower RT during both Static and Dynamic reaction, and smaller differences in RT and phasing between COP, trunk, and head motion. The results of this study suggest that the elderly adopted more rigid coordination strategies compared to the young when executing a rapid change in direction of whole body motion. The rigid movement strategy of the elderly was presumably generated in an effort to compensate for increased challenge to the maintenance of stability.     

Constrained action selection in children with developmental coordination disorder

The effect of advance ('precue') information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n=10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic.     

Acquired flavour preferences: contextual control of adaptation-level effects

This experiment investigated the role of context in the expression of conditioned flavour preferences. Rats were trained on a mixture of almond and sucrose and were then given intermixed exposures to almond in one context (Context A) and to sucrose in a second context (Context S). Finally, choice tests were given in both contexts, with one group given almond-versus-water tests and the other almond + sucrose-versus-sucrose tests. Preference for almond over water was greater in Context A than in Context S. Conversely, preference for almond + sucrose over sucrose was greater in Context S than in Context A. These results suggest that the perceived sweetness of a flavour depends on the context in which it is presented and confirm that expression of a flavour preference depends on the type of test employed.     

Why the unskilled are unaware: Further explorations of (absent) self-insight among the incompetent

People are typically overly optimistic when evaluating the quality of their performance on social and intellectual tasks. In particular, poor performers grossly overestimate their performances because their incompetence deprives them of the skills needed to recognize their deficits. Five studies demonstrated that poor performers lack insight into their shortcomings even in real world settings and when given incentives to be accurate. An additional meta-analysis showed that it was lack of insight into their own errors (and not mistaken assessments of their peers) that led to overly optimistic estimates among poor performers. Along the way, these studies ruled out recent alternative accounts that have been proposed to explain why poor performers hold such positive impressions of their performance.     

Inference generation in young,young–old and old–old adults: evidence for semantic architecture stability

Participants (31 young, 27 young–old, and 28 old–old) read 12 narratives, pausing periodically to think aloud. The resulting protocols were analysed for 17 types of inferences and for non‐content (off‐target) information. Factor analysis yielded three inference factors: character, causal and physical. Age difference across these factors were not significant, suggesting that inferential processing architecture may be stable. Each narrative also included an unfamiliar word. Immediately following each narrative, four definition choices and a definition rating scale were presented. The definition scores of old–old adults were lower than young and young–old. In addition, definition scores were negatively related to non‐content comment counts. Taken together, these findings suggest that off‐target working‐memory intrusions may interfere with interpretation specificity in older adults even though semantic architecture remains stable. This study extends the aging and inference literature by addressing age‐related changes across categories of inferential processing and by including a sample of old–old adults. Copyright © 2007 John Wiley & Sons, Ltd.     

The role of elaboration in the persistence of awareness for degraded objects

When a fragmented line-drawing of an object moves relative to a background of randomly oriented lines, the previously hidden object can be segregated from the background and consequently enters awareness. In this shape-from-motion paradigm, the percept of the object briefly persists after the motion stops, demonstrating the maintenance of a bound percept in awareness. This study investigated how the manipulation of object features that are crucial to recognition influences both the binding process and the maintenance of objects in awareness. Overall, we found that objects that took longer to recognize (i.e., objects missing their vertices) were nonetheless maintained in awareness for longer. We argue that this effect is mediated by additional elaborative processing that is required to bind these less recognizable forms, which generates stronger and more robust representations. These representations are then more easily maintained in awareness, suggesting an important role of elaborative mechanisms for conscious representations.     

Human Capabilities and the Ethics of Debt

The Journal of Value Inquiry -