Caffeine as a performance-enhancing drug in rats: sex, dose, housing, and task considerations

Past animal studies of the performance-enhancing properties of stimulant drugs, such as caffeine, may have suffered from a number of procedural and ethical problems. For example. the housing condition of the animals was often not taken into consideration. As well, endurance tests, such as the forced swim task, sometimes involved ethically (and procedurally) questionable interference with natural swimming behaviour. Some of the manipulations, such as attaching a weight to the swimming animal's tail to increase the difficulty of the task and using mortality as a dependent variable, seem grotesque, even unnecessary. In this experiment, the performance-enhancing effects of caffeine in a modified forced swim task and a dominance task were evaluated using male and female rats as subjects (N=60), housed in either enriched or isolated environments. Analysis indicated that rats respond to caffeine as an interactive function of sex, housing, dose, and task characteristics. It was concluded that performance-enhancing properties of stimulant drugs may be the result of a complex interplay of variables, making simple generalizations questionable.     

Executive and visuospatial sketchpad resources in euthymic bipolar disorder: Implications for visuospatial working memory architecture

Visuospatial working memory theory is used to interpret the cognitive impairment in euthymic bipolar disorder. Such patients show deficits in the Corsi Blocks Test (CBT) and executive control. To understand these deficits, 20 euthymic bipolar patients and controls were administered the CBT, Visual Patterns Test (VPT), and a new visual memory task designed to make minimal demands on executive resources. Initial analyses validated the visual memory task and implicated executive involvement in the CBT and VPT. Subsequent analyses on a number of tests confirmed CBT and executive deficits while performance was normal on the VPT and visual memory test. ANCOVA indicated that impaired executive function underpinned patients' CBT performance. Implications for the interface between executive and slave systems of working memory are discussed.     

Learning perceptual organization in infancy

It has been demonstrated that older infants (6- to 7-month-olds), but not younger infants (3- to 4-month-olds), use form similarity to organize stimuli consisting of X and O elements. We investigated whether utilization of form similarity is governed by maturation or experience by contrasting how infants perform when familiarized with a single exemplar versus multiple exemplars depicting a particular organization. In Experiment 1, 3- to 4-month-olds failed to organize alternating columns or rows of squares and diamonds or Hs and Is, respectively. In Experiment 2, same-aged infants familiarized with all three patterns (X-O, square-diamond, H-I) displayed evidence of organization. The results suggest that 3- to 4-month-olds can use form similarity to organize visual patterns in a concept-formation task. The findings imply that perceptual organization based on form similarity is learned through experience with multiple patterns depicting a common arrangement, rather than immediately apprehended in an individual pattern.     

Development of form similarity as a Gestalt grouping principle in infancy

Given evidence demonstrating that infants 3 months of age and younger can utilize the Gestalt principle of lightness similarity to group visually presented elements into organized percepts, four experiments using the familiarization/novelty-preference procedure were conducted to determine whether infants can also organize visual pattern information in accord with the Gestalt principle of form similarity. In Experiments 1 and 2, 6- to 7-month-olds, but not 3- to 4-month-olds, presented with generalization and discrimination tasks involving arrays of X and O elements responded as if they organized the elements into columns or rows based on form similarity. Experiments 3 and 4 demonstrated that the failure of the young infants to use form similarity was not due to insufficient processing time or the inability to discriminate between the individual X and O elements. The results suggest that different Gestalt principles may become functional over different time courses of development, and that not all principles are automatically deployed in the manner originally proposed by Gestalt theorists.     

Preferences Regarding Targeted Education and Risk Assessment in People with a Family History of Major Depressive Disorder

Genetic testing for susceptibility to major depressive disorder (MDD) is not available for clinical use at present. Given this, family history remains the best predictor for development of MDD, and family-history-based risk assessment and information about familial aspects of MDD may be useful to clients at increased risk for MDD attending for genetic counseling. This study uses a mixed-methods design to assess the information needs and preferences of people at increased familial risk for MDD. Telephone interviews were conducted with 23 individuals, who had at least one first-degree relative with MDD and were recruited through advertisements placed on depression education websites. The most preferred way to access depression information was via the internet (87 % of participants), although this preference may have been due to the internet-based recruitment method. The second most preferred dissemination strategy (56 %) was face-to-face delivery through a health professional, including genetic counselors. Individuals reported a need for information about etiology and development of MDD, reproductive decision-making, early detection of symptoms and risk-reducing strategies. Nearly all participants expressed an interest in risk assessment. The present study found evidence of a high level of interest for information targeted to people at increased familial risk for MDD. Genetic counselors are likely to be called upon increasingly to provide supportive counseling to assist clients at increased familial risk in interpreting and contextualizing such information once it becomes available.     

An Occupational Therapy Support Service for University Students With Asperger's Syndrome (AS)

Students with Asperger's Syndrome (AS) face challenges, within third-level education, related to the person, environment, and occupation. This study describes an occupational therapy (OT) service that aims to enhance the interplay between the person (i.e., the student) and his/her occupation within a given context (i.e., college environment). A chart review and Student Satisfaction Survey was used to identify the demographics, concerns, and goals of the students using it. It was found that goals and concerns shift according to students' stage in college and recommends that services employ a student-centered, flexible approach responsive to the particular concerns of these students.     

On the nature of fear of falling in Parkinson's disease

In the elderly, fear of falling (FoF) can lead to activity restriction and affect quality of life (QoL). Our aim was to identify the characteristics of FoF in Parkinson's disease and assess its impact on QoL. We assessed FoF in 130 patients with Parkinson's disease (PD) on scales measuring perceived self-efficacy in performing a range of activities (FES), perceived consequences of falling (CoF), and activity avoidance (SAFFE). A significant difference was found in FoF between PD patients who had previously fallen and those who had not and between frequent and infrequent fallers. Patient-rated disability significantly influenced FoF. Difficulty in rising from a chair, difficulty turning, start hesitation, festination, loss of balance, and shuffling were the specific mobility problems which were associated with greater FoF in PD. Disability was the main predictor of FoF, additionally depression predicted perceived consequences of falling, while anxiety predicted activity avoidance. The FoF measures explained 65% of the variance of QoL in PD, highlighting the clinical importance of FoF. These results have implications for the clinical management of FoF in PD.     

Transfer of associative grouping to novel perceptual contexts in infancy

Learning can be highly adaptive if associations learned in one context are generalized to novel contexts. We examined the development of such generalization in infancy in the context of grouping. In Experiment 1, 3- to 4-month-olds and 6- to 7-month-olds were habituated to shapes grouped via the organizational principle of common region and were tested with familiar and novel pairs as determined by the principle of proximity. Older infants generalized from common region to proximity, but younger infants did not. Younger infants failed to generalize when the task was easier (Experiment 2), and their failure was not due to inability to group via proximity (Experiment 3). However, in Experiment 4, even younger infants generalized grouping on the basis of connectedness to proximity. Thus, the ability to transfer learned associations of shapes to novel contexts is evident early in life, although it continues to undergo quantitative change during infancy. Moreover, the operation of this generalization mechanism may be induced by means of bootstrapping onto functional organizational principles, which is consistent with a developmental framework in which core processes scaffold learning.     

The influence of ingroup/outgroup categorization on same- and other-race face processing: The moderating role of inter- versus intra-racial context

We investigated the impact of ingroup/outgroup categorization on the encoding of same-race and other-race faces presented in inter-racial and intra-racial contexts (Experiments 1 and 2, respectively). White participants performed a same/different matching task on pairs of upright and inverted faces that were either same-race (White) or other-race (Black), and labeled as being from the same university or a different university. In Experiment 1, the same- and other-race faces were intermixed. For other-race faces, participants demonstrated greater configural processing following same- than other-university labeling. Same-race faces showed strong configural coding irrespective of the university labeling. In Experiment 2, faces were blocked by race. Participants demonstrated greater configural processing of same- than other-university faces, but now for both same- and other-race faces. These results demonstrate that other-race face processing is sensitive to non-racial ingroup/outgroup status regardless of racial context, but that the sensitivity of same-race face processing to the same cues depends on the racial context in which targets are encountered.     

Does changing the reference frame affect infant categorization of the spatial relation BETWEEN?

Past research has shown that variation in the target objects depicting a given spatial relation disrupts the formation of a category representation for that relation. In the current research, we asked whether changing the orientation of the referent frame depicting the spatial relation would also disrupt the formation of a category representation for that relation. Experiments 1 to 3 provided evidence that 6- and 7-month-olds formed a category representation for BETWEEN when a diamond shape was depicted in different locations between two vertical or horizontal reference bars during familiarization and in a novel location between the same orientation of bars during test. By contrast, in Experiment 4, same-age infants did not form a category representation for BETWEEN when the diamond shape was depicted between two vertical (or horizontal) bars during familiarization and between two horizontal (or vertical) bars during test. Moreover, in Experiment 5, 9- and 10-month-olds did form a category representation for BETWEEN when the orientation of the referent bars depicting the relation changed from familiarization to test. The findings suggest that the formation of category representations for spatial relations by infants is affected by changes to either target (figure) or referent (ground).