Visual homing in the absence of feature-based landmark information

Despite that fact that landmarks play a prominent role in human navigation, experimental evidence on how landmarks are selected and defined by human navigators remains elusive. Indeed, the concept of a ‘landmark’ is itself not entirely clear. In everyday language, the term landmark refers to salient, distinguishable, and usually nameable objects, rendering the problem of landmark recognition a special case of the general object recognition problem. In contrast, in the insect and robot literature, this notion of landmarks is often replaced by the “local position information” [e.g., Trullier, O., Wiener, S., Berthoz, A., &; Meyer, J.-A. (1997). Biologically based artificial navigation systems: Review and prospects. Progress in Neurobiology, 51, 483–544], referring to the entire set of sensor readings obtained at one location. This set may then serve as a characteristic of the particular location. Honey bees have been shown to base place recognition and homing on a snapshot-like memory of the place’s visual environment, not on the distances to recognized objects [Cartwright, B., &; Collett, T. (1983). Landmark learning in bees. Experiments and models. Journal of Comparative Physiology A, 151, 521–543]. A number of theoretical models of snapshot-based homing [e.g., Franz, M., Schölkopf, B., Mallot, H. A., Bülthoff, H. H. (1998). Where did I take that snapshot? Scene-based homing by image matching. Biological Cybernetics, 79, 191–202; Vardy, A., &; Möller, R. (2005). Biologically plausible visual homing methods based on optical flow techniques. Connection Science, 17, 47–89] predict that the accuracy of snapshot-based homing should depend on image contrast. For rodent hippocampal place fields, models have been developed using additional image information such as three-dimensional depth and allocentric orientations (e.g., room axes) and are thus less sensitive to image contrast and noise [e.g. Barry, C., Lever, C., Hayman, R., Hartley, T., Burton, S., O’Keefe, J., et al. (2006). The boundary vector cell model of place cell firing and spatial memory. Reviews in the Neurosciences, 17, 71–79]. Here, we study human visual homing in a virtual environment void of objects and readily detected image features. The environment was a circular room with a homogenous colour gradient covering the wall and uniform floor and ceiling. Subjects were able to approach remembered places. Accuracy decreased with colour gradient modulation and room size, in qualitative agreement with the snapshot model but not with other models of place recognition. We conclude that human memory for places can make use of a snapshot algorithm.     

Age differences between children and young adults in the dynamics of dual-task prioritization: body (balance) versus mind (memory)

Task prioritization can lead to trade-off patterns in dual-task situations. The authors compared dual-task performances in 9- and 11-year-old children and young adults performing a cognitive task and a motor task concurrently. The motor task required balancing on an ankle-disc board. Two cognitive tasks measured working memory and episodic memory at difficulty levels individually adjusted during the course of extensive training. Adults showed performance decrements in both task domains under dual-task conditions. In contrast, children showed decrements only in the cognitive tasks but actually swayed less under dual-task than under single-task conditions and continued to reduce their body sway even when instructed to focus on the cognitive task. The authors argue that children perform closer to their stability boundaries in the balance task and therefore prioritize protection of their balance under dual-task conditions.     

Selective and protracted effect of nifedipine on fear memory extinction correlates with induced stress response

Memory extinction, defined as a decrease of a conditioned response as a function of a non-reinforced conditioned stimulus presentation, has high biological and clinical relevance. Extinction is not a passive reversing or erasing of the plasticity associated with acquisition, but a novel, active learning process. Nifedipine blocks L-type voltage gated calcium channels (LVGCC) and has been shown previously to selectively interfere with the extinction, but not the acquisition, of fear memory. We studied here the effect of retrograde and anterograde shifts of nifedipine application, with respect to an extinction training, on the extinction of fear conditioning. Subcutaneous injection of 30 mg/kg nifedipine, at least up to 4 h before the extinction session, significantly impaired extinction, as did intraperitoneal injection of 15 mg/kg nifedipine, at least up to 2 h before extinction training. However, the injection of nifedipine also induced a strong and protracted stress response. The pharmacokinetics of nifedipine suggest that it was mainly this stress response that triggered the specific inhibition of extinction, not the blockade of LVGCC in the brain. Our results support recent findings that stress selectively interferes with the extinction, but not the acquisition, of fear memory. They also indicate that a pharmacological approach is not sufficient to study the role of brain LVGCC in learning and memory. Further research using specific genetically modified animals is necessary to delineate the role of LVGCC in fear memory extinction.     

Defining Treatment Outcomes in Pediatric Obsessive-Compulsive Disorder Using a Self-Report Scale

This study examined benchmarks of treatment response and clinical remission on the Obsessive Compulsive Inventory–Child Version (OCI-CV) for youth with obsessive-compulsive disorder (OCD). Participants were 91 youth who enrolled in a randomized controlled trial that examined the benefit of augmenting cognitive behavior therapy (CBT) with either d-cycloserine or placebo. Youth completed the OCI-CV at baseline, Week 4 (prior to initiating exposure therapy), and posttreatment. Receiver operator curve (ROC) analyses examined optimal benchmarks for treatment response and clinical remission as identified by independent evaluators at the posttreatment assessment using the Clinical Global Impression (CGI) scales of Improvement (CGI-Improvement), Severity (CGI-Severity), and Children’s Yale-Brown Obsessive Compulsive Scale (CY-BOCS). Optimal benchmarks for treatment response were a 20%–25% reduction in the OCI-CV total score. Meanwhile, optimal benchmarks for remission were a 55%–65% reduction in the OCI-CV total score and a posttreatment total score ≤ 6-8. OCI-CV benchmarks exhibited moderate agreement with the CY-BOCS for treatment response and clinical remission. Meanwhile, fair agreement was observed for response and remission with CGI scales. A lower pretreatment OCI-CV total score was associated with less agreement between classification approaches. Findings provide benchmarks for classifying treatment response and clinical remission in an efficient manner. Given the moderate agreement between the CY-BOCS and OCI-CV benchmarks, the OCI-CV may serve as a useful alternative when clinician-rated scales cannot be administered due to limited resources (e.g., time, training). Thus, evidence-based measurement can be incorporated to monitor therapeutic response and remission in clinical practice.     

Illegitimacy moderates the effects of power on approach

A wealth of research has found that power leads to behavioral approach and action. Four experiments demonstrate that this link between power and approach is broken when the power relationship is illegitimate. When power was primed to be legitimate or when power positions were assigned legitimately, the powerful demonstrated more approach than the powerless. However, when power was experienced as illegitimate, the powerless displayed as much approach as, or even more approach than, the powerful. This moderating effect of legitimacy occurred regardless of whether power and legitimacy were manipulated through experiential primes, semantic primes, or role manipulations. It held true for behavioral approach (Experiment 1) and two effects associated with it: the propensity to negotiate (Experiment 2) and risk preferences (Experiments 3 and 4). These findings demonstrate that how power is conceptualized, acquired, and wielded determines its psychological consequences and add insight into not only when but also why power leads to approach.     

Ethnicity-Related Stressors and Mental Health in Latino Americans: The Moderating Role of Parental Racial Socialization

The current study examined the moderating role of proactive and reactive parental racial socialization on the relationship between Latino American college students' mental health and 3 ethnicity-related stressors: perceived racial discrimination, stereotype confirmation concern, and own-group conformity pressure. In hierarchical regression, greater stereotype confirmation concern predicted more mental distress in 105 Latino American college students. Both proactive and reactive racial socialization moderated the effect of own-group conformity pressure on anxiety and loss of behavioral/emotional control. Specifically, greater proactive and reactive racial socialization predicted more mental distress under greater own-group conformity pressure. Findings are interpreted in a college environment of ethnic diversity and a context of acculturative stress.     

The Institute for Music Physiology and Musicians’ Medicine

The Institute of Music Physiology and Musicians' Medicine of the University of Music and Drama in Hannover, Germany, is a unique Institution in Europe whose scope includes teaching the basics of music physiology and musicians' medicine and research into the physiological and neurobiological principles of professional music performance and music perception. Furthermore, the institute conducts research into the causes of occupational injuries in musicians and provides means for prevention, diagnosis and treatment of such injuries.     

Using a modified constant prompt-delay procedure to teach spelling to students with physical disabilities

Current research suggests that constant delay is an effective means of teaching students through near-errorless learning. The current study examined how procedures used in previous research may be modified so that constant delay can be implemented with students who have physical disabilities that prevent them from engaging in fluent academic responding. A multiple baseline design with probes was used to assess the effectiveness of a modified constant-delay procedure in teaching spelling to students with physical disabilities. This procedure was found to be effective for all 3 students.