Selection of tool diameter by New Caledonian crows<Emphasis Type="Italic"> Corvus moneduloides</Emphasis>

One important element of complex and flexible tool use, particularly where tool manufacture is involved, is the ability to select or manufacture appropriate tools anticipating the needs of any given task—an ability that has been rarely tested in non-primates. We examine aspects of this ability in New Caledonian crows—a species known to be extraordinary tool users and manufacturers. In a 2002 study, Chappell and Kacelnik showed that these crows were able to select a tool of the appropriate length for a task among a set of different lengths, and in 2002, Weir, Chappell and Kacelnik showed that New Caledonian crows were able to shape unfamiliar materials to create a usable tool for a specific task. Here we examine their handling of tool diameter. In experiment 1, we show that when facing three loose sticks that were usable as tools, they preferred the thinnest one. When the three sticks were presented so that one was loose and the other two in a bundle, they only disassembled the bundle when their preferred tool was tied. In experiment 2, we show that they manufacture, and modify during use, a tool of a suitable diameter from a tree branch, according to the diameter of the hole through which the tool will have to be inserted. These results add to the developing picture of New Caledonian crows as sophisticated tool users and manufacturers, having an advanced level of folk physics.Electronic Supplementary Material Supplementary material is available in the online version of this article at     

A Web-based family problem-solving intervention for families of children with traumatic brain injury

We developed a Web-based intervention for pediatric traumatic brain injury (TBI) and examined its feasibility for participants with limited computer experience. Six families, including parents, siblings, and children with TBI, were given computers, Web cameras, and high-speed Internet access. Weekly videoconferences with the therapist were conducted after participants completed on-line interactive experiences on problem solving, communication, and TBI-specific behavior management. Families were assigned to videoconference with NetMeeting (iBOT cameras) or ViaVideo. Participants ranked the Web site and videoconferences as moderately to very easy to use. ViaVideo participants rated videoconferencing significantly more favorably relative to face-to-face meetings than did NetMeeting participants. Both the Web site and videoconferencing were rated as very helpful. All families demonstrated improved outcomes on one or more target behaviors, including increased understanding of the injury and improved parent-child relationships. All parents and siblings and all but 1 child with TBI said they would recommend the program to others. We conclude that a face-to-face intervention can be successfully adapted to the Web for families with varied computer experience.     

Implementing communication between Windows PCs and test equipment using RS-232 and Borland C+ + Builder

Modern experiments in the behavioral sciences frequently employ several items of electronic equipment such as computers, monitoring devices, stimulus presentation equipment, and response collection systems. In many cases it would be advantageous for these items to communicate directly with each other. Such communication may facilitate greater automation of experiments (i.e., reduced experimenter influences during the experiment), more precise experiment control (i.e., superior timing and synchronization capabilities of electronic devices), and greater accuracy of data collection (i.e., reduced ambiguity of participant responses). Many electronic experiment devices already provide external interfacesthrough which communication with other devices can be implemented. The most common is based on the RS-232 protocol, which is also found in all standard PCs. Therefore, Microsoft Windows based computers can be programmed to control experiments by communicating directly with electronic experiment devices. We show how to implement this RS-232 interconnection between devices and a Windows PC using currently available software tools.     

Predictors of picture naming speed

We report the results of a large-scale picture naming experiment in which we evaluated the potential contribution of nine theoretically relevant factors to naming latencies. The experiment included a large number of items and a large sample of participants. In order to make this experiment as similar as possile to classic picture naming experiments, participants were familiarizedwith the materials during a training session. Speeded naming latencies were determined by a software key on the basis of the digital recording of the responses. The effects of various variables on these latencies were assessed with multiple regression techniques, using a repeated measures design. The interpretation of the observed effects is discussed in relation to previous studies and current views on lexical access during speech production.     

Perception of biological motion: A stimulus set of human point-light actions

We present a set of stimuli representing human actions under point-light conditions, as seen from different viewpoints. The set contains 22 fairly short, well-delineated, and visually “loopable” actions. For each action, we provide movie files from five different viewpoints as well as a text file with the three spatial coordinates of the point lights, allowing researchers to construct customized versions. The full set of stimuli may be downloaded fromwww.psychonomic.org/archive/.     

Computing aspects of power for multiple regression

Rules of thumb for power in multiple regression research abound. Most such rules dictate the necessary sample size, but they are based only upon the number of predictor variables, usually ignoring other critical factors necessary to compute power accurately. Other guides to power in multiple regression typically use approximate rather than precise equations for the underlying distribution; entail complex preparatory computations; require interpolation with tabular presentation formats; run only under software such as Mathmatica or SAS that may not be immediately available to the user; or are sold to the user as parts of power computation packages. In contrast, the program we offer herein is immediately downloadable at no charge, runs under Windows, is interactive, self-explanatory, flexible to fit the user’s own regression problems, and is as accurate as single precision computation ordinarily permits.     

Touchscreen-enhanced visual learning in rats

The efficiency of traditional levers and of modern touchscreen technology for training rats on a computerized visual discrimination was studied in a series of observations. When compared with a lever-based discrimination procedure, the use of touchscreens supported the faster development of signal tracking behavior and acquisition of a two-stimulus simultaneous visual discrimination. It did not affect the final level of accuracy. Factors related to spatial proximity of the responses with the stimuli, sign-tracking, and increased ease of touchscreen motor responses were suggested as possible reasons for the touchscreen training advantage. This increased efficiency allows large numbers of animals to be tested quickly, a necessary requirement for studies involving genetic and physiological interventions.     

VIZ: The visualization assessment and training Web site

The VIZ Website(http:/viz.bd.psu.ech]/viz/) was developed as a free and open portal for assessment and training of spatial skills. Using Macromedia Authorware, it allows the collection of response times and accuracies from four spatial tasks: mental rotation, paper folding, water level judgments, and spatial working memory. Additional tasks are under development. The site has been used for a variety of teaching and research purposes. For example, incoming engineering students have completed the tasks to assess their spatial skills before beginning their graphics courses. Those with poorer skills can then receive the appropriate remedial instruction. The VIZ site has also been used to teach about spatial cognition and to do research outside the laboratory setting. Finally, we are using the site to conduct basic research on spatial cognition, including an examination of the factors that may reduce gender differences in performance.