Statistical classification of black-capped (Poecile atricapillus) and mountain chickadee (Poecile gambeli) call notes

Both black-capped (Poecile atricapillus) and mountain chickadees (Poecile gambeli) produce a chick-a-dee call that consists of several distinct note types. In some regions, these 2 species live sympatrically, and it has been shown that 1 species will respond weakly to songs of the other. This suggests that chickadee song, and potentially other of their vocalizations, contains species-specific information. We tested the possibility that call notes were acoustically sufficient for species identification. Black-capped and mountain non-D notes were summarized as a set of 9 features and then analyzed by linear discriminant analysis. Linear discriminant analysis was able to use these notes to identify species with 100% accuracy. We repeated this approach, but with black-capped and mountain D notes that were summarized as a set of 4 features. Linear discriminant analysis was able to use these notes to identify species with 94% accuracy. This demonstrates that any of the note types in these chickadee calls possesses sufficient information for species classification.     

Do you remember proposing marriage to the Pepsi machine? False recollections from a campus walk

During a campus walk, participants were given familiar or bizarre action statements (e.g., “Check the Pepsi machine for change” vs. “Propose marriage to the Pepsi machine”) with instructions either to perform the actions or imagine performing the actions (Group 1) or to watch the experimenter perform the actions or imagine the experimenter performing the actions (Group 2). One day later, some actions were repeated, along with new actions, on a second walk. Two weeks later, the participants took a recognition test for actions presented during the first walk, and they specified whether a recognized action was imagined or performed. Imagining themselves or the experimenter performing familiar or bizarre actions just once led to false recollections of performance for both types of actions. This study extends previous research on imagination inflation by demonstrating that these false performance recollections can occur in a natural, real-life setting following just one imagining.     

On the Exclusivity Implicature of ‘Or’ or on the Meaning of Eating Strawberries

This paper is a contribution to the program of constructing formal representations of pragmatic aspects of human reasoning. We propose a formalization within the framework of Adaptive Logics of the exclusivity implicature governing the connective ‘or’.Keywords: exclusivity implicature, Adaptive Logics.     

Acquiring new spatial intuitions: learning to reason about rotations

There are certain simple rotations of objects that most people cannot reason about accurately. Reliable gaps in the understanding of a fundamental physical domain raise the question of how learning to reason in that domain might proceed. Using virtual reality techniques, this project investigated the nature of learning to reason across the domain of simple rotations. Learning consisted of the acquisition of spatial intuitions: there was encoding of useful spatiotemporal information in specific problem types and a gradual accumulation of this understanding across the domain. This pattern of learning through the accumulation of intuitions is especially interesting for rotational motion, in which an elegant domain-wide kinematics is available to support insightful learning. Individual ability to reason about rotations correlated highly with mastery motivation, skill in fluid reasoning, and skill in reasoning about spatial transformations. Thus, general cognitive advantages aided the understanding of individual rotations without guaranteeing immediate generalization across the domain.     

Young children with autism show atypical brain responses to fearful versus neutral facial expressions of emotion

Evidence suggests that autism is associated with impaired emotion perception, but it is unknown how early such impairments are evident. Furthermore, most studies that have assessed emotion perception in children with autism have required verbal responses, making results difficult to interpret. This study utilized high-density event-related potentials (ERPs) to investigate whether 3-4-year-old children with autism spectrum disorder (ASD) show differential brain activity to fear versus neutral facial expressions. It has been shown that normal infants as young as 7 months of age show differential brain responses to faces expressing different emotions. ERPs were recorded while children passively viewed photos of an unfamiliar woman posing a neutral and a prototypic fear expression. The sample consisted of 29 3-4-year-old children with ASD and 22 chronological age-matched children with typical development. Typically developing children exhibited a larger early negative component (N300) to the fear than to the neutral face. In contrast, children with ASD did not show the difference in amplitude of this early ERP component to the fear versus neutral face. For a later component, typically developing children exhibited a larger negative slow wave (NSW) to the fear than to the neutral face, whereas children with autism did not show a differential NSW to the two stimuli. In children with ASD, faster speed of early processing (i. e. N300 latency) of the fear face was associated with better performance on tasks assessing social attention (social orienting, joint attention and attention to distress). These data suggest that children with ASD, as young as 3 years of age, show a disordered pattern of neural responses to emotional stimuli.     

Effects of Self-Monitoring on On-Task Behaviors of At-Risk Middle School Students

The purposes of this study were to evaluate the effects of self-monitoring on increasing the on-task behaviors of four at-risk middle school students, and to examine its indirect effects on academic performance. Additionally, we attempted to develop and validate cost- and time-efficient procedures that typical classroom teachers could use. The data from a multiple baseline design across three academic settings, replicated with four students, revealed immediate increases in on-task behavior as each student began to self-monitor in each sequential setting. The data also revealed slightly higher levels of academic performance and, in most instances, gradually accelerating trends. These findings suggest that self-monitoring is a cost- and time-efficient procedure that classroom teachers can use to teach at-risk students to manage their own behaviors.     

Imitation and social responsiveness in autistic children

Fifteen autistic children, ages 4–6 years, participated in the present study. Imitation and object permanence skills were assessed. Language and social behaviors were observed during free play. Children were also exposed to three interactive procedures that differed in developmental sophistication. The experimenter either (1) simultaneously imitated the child's actions, (2) modeled a familiar action, or (3) modeled a novel action. It was found that the autistic children who had a low level of imitative ability (Piaget's Stages 2–3) were more socially responsive, showed more eye contact, and played with toys in a less perseverative manner when the experimenter imitated their behavior than when the experimenter modeled either a familiar or a novel action. When the experimenter modeled a familiar as opposed to a novel action, these children were more likely to spontaneously imitate the experimenter. The autistic children with more highly developed imitation skills, however, responded similarly to all conditions. They also were generally more socially and verbally responsive. These results suggest that developmental status is an important variable in designing intervention programs for severely impaired children.We would like to express our appreciation to the autistic children who participated in the study, and to their parents, and to the staff of the T.E.A.C.C.H. Division, University of North Carolina for their help and cooperation. We would also like to thank Karen Cotten, Pete Giordano, Vickie Hall, Lee Hendrix, Shari Jernigan, Kevin Lumley, Cindy Seagroves, Sheryl Solomon, Kathy Stetson, and Jeannie Teasley for their assistance in data collection and coding, and Mary Lynn Eckert and Anne Stanford for their secretarial assistance. Cathy Dent provided helpful suggestions on earlier drafts of the paper. Support was provided by UNC Research Council.     

Response specificity in animal timing.

The stimuli that control responding in the peak procedure were investigated by training rats, in separate sessions, to make two different responses for food reinforcement. During one type of session, lever pressing was normally reinforced 32 s after the onset of a light. During the other type of session, chain pulling was normally reinforced either 8 s after the onset of one auditory cue or 128 s after the onset of a different auditory cue. For both types of sessions, only the appropriate manipulandum was available, and 20% of the trials lasted 240 s and involved no response-contingent consequences. Rats were then tested with the auditory cues in the presence of the lever and the light in the presence of the chain. If the time of reinforcement associated with each stimulus was learned, response rates should peak at these times during transfer testing. However, if a specific response pattern was learned for each stimulus, little transfer should occur. The results did not clearly support either prediction, leading to the conclusion that both a representation of the time of reinforcement and the rat's own behavior may control responding in this situation.