N-Watch: A program for deriving neighborhood size and other psycholinguistic statistics

This article describes a Windows program that enables users to obtain a broad range of statistics concerning the properties of word and nonword stimuli, including measures of word frequency, orthographic similarity, orthographic and phonological structure, age of acquisition, and imageability. It is designed for use by researchers in psycholinguistics, particularly those concerned with recognition of isolated words. The program computes measures of orthographic similarity on line, either with respect to a default vocabulary of 30,605 words or to a vocabulary specified by the user. In addition to providing standard orthographic neighborhood measures, the program can be used to obtain information about other forms of orthographic similarity, such as transposed-letter similarity and embedded-word similarity. It is available, free of charge, from the following Web site: http://www.maccs.mq.edu.au/≈colin/N-Watch/.     

Semantic feature production norms for a large set of living and nonliving things

Semantic features have provided insight into numerous behavioral phenomena concerning concepts, categorization, and semantic memory in adults, children, and neuropsychological populations. Numerous theories and models in these areas are based on representations and computations involving semantic features. Consequently, empirically derived semantic feature production norms have played, and continue to play, a highly useful role in these domains. This article describes a set of feature norms collected from approximately 725 participants for 541 living (dog) and nonliving (chair) basic-level concepts, the largest such set of norms developed to date. This article describes the norms and numerous statistics associated with them. Our aim is to make these norms available to facilitate other research, while obviating the need to repeat the labor-intensive methods involved in collecting and analyzing such norms. The full set of norms may be downloaded from www.psychonomic.org/archive.     

Generating complex three-dimensional stimuli (Greebles) for haptic expertise training

An apparatus is described that accurately measures response times and video records hand movements during haptic object recognition using complex three-dimensional (3-D) forms. The apparatus was used for training participants to become expert at perceptual judgments of 3-D objects (Greebles) using only their sense of touch. Inspiration came from previous visual experiments, and therefore training and testing protocols that were similar to the earlier visual procedures were used. Two sets of Greebles were created. One set (clay Greebles) was hand crafted from clay, and the other (plastic Greebles) was machine created using rapid prototyping technology. Differences between these object creation techniques and their impact on perceptual expertise training are discussed. The full set of these stimuli may be downloaded from www.psychonomic.org/archive/.     

An on-line task for contrasting auditory processing in the verbal and nonverbal domains and norms for younger and older adults

Contrasting linguistic and nonlinguistic processing has been of interest to many researchers with different scientific, theoretical, or clinical questions. However, previous work on this type of comparative analysis and experimentation has been limited. In particular, little is known about the differences and similarities between the perceptual, cognitive, and neural processing of nonverbal environmental sounds and that of speech sounds. With the aim of contrasting verbal and nonverbal processing in the auditory modality, we developed a new on-line measure that can be administered to subjects from different clinical, neurological, or sociocultural groups. This is an on-line task of sound to picture matching, in which the sounds are either environmental sounds or their linguistic equivalents and which is controlled for potential task and item confounds across the two sound types. Here, we describe the design and development of our measure and report norming data for healthy subjects from two different adult age groups: younger adults (18–24 years of age) and older adults (54–78 years of age). We also outline other populations to which the test has been or is being administered. In addition to the results reported here, the test can be useful to other researchers who are interested in systematically contrasting verbal and nonverbal auditory processing in other populations.     

Structural brain variation,age, and response time

Response time (RT) generally slows with aging, but the contribution of structural brain changes to this slowing is unknown. We used voxel-based morphometry (VBM) to determine gray matter (GM) and white matter (WM) brain volumes in 9 middle-aged adults (38–58 years old) and 9 seniors (66–82 years old). We correlated brain volumes with RT assessed in both a simple visual stimulus-response task and a visual continuous recognition memory task. No GM correlations with simple RT were significant; there was one WM correlation in the right fusiform gyrus. In the memory task, faster RT was correlated (p<.05, corrected) with less GM in the globus pallidus, the parahippocampus, and the thalamus for both groups. Several Brodmann areas (BA) differed between the groups such that in each area, less GM was correlated with slower RTs in the middle-aged group but with faster RTs in the senior group (BAs 19, 37, 46, 9, 8, 6, 13, 10, 41, and 7). The results suggest that individual differences in specific brain structure volumes should be considered as potential moderating factors in cognitive brain imaging studies.     

WebDiP: A tool for information search experiments on the World-Wide Web

We describe WebDiP (Web Decision Processes)&#x2014;an open-source, online tool&#x2014;which enables a researcher to track participants while they search for information in a database, available through the Internet. After various instructions on setup and configuration are given, a detailed view of WebDiP explains the system’s technical features. Furthermore, other open-source tools are mentioned that helped in programming WebDiP, running it, or analyzing data gathered with it. We present new approaches of how open-source thinking can be incorporated into a research process and discuss future perspectives of WebDiP.     

Using the score method to construct asymmetric confidence intervals: An SAS program for content validation in scale development

Expert review sessions are often conducted to determine the content validity of scale items. The accurate quantification of content validity is usually limited by a relatively small number of experts as well as by a small number of rating categories. These factors, combined with the bounded and discrete nature of rating scale categories, hinder use of traditional methods for computing standard errors and confidence intervals. Using an application of the score method, researchers can construct an asymmetric interval that is better suited for these situations. SAS code is provided to automate the computations, and a discussion of two methods for using the obtained results for content validation decisionmaking follows.     

Laboratory behavioral measures of impulsivity

Previous research and theory have conceptualized impulsivity as a multifaceted construct that requires multiple modes of measurement for accurate assessment. This article describes a software package that includes four paradigms for measuring multiple and unique aspects of impulsivity. Specifically, four tasks are described: (1) the two choice impulsivity paradigm, (2) the single key impulsivity paradigm, (3) the GoStop impulsivity paradigm, and (4) the time paradigm. These tasks measure processes related to the capacity to tolerate delay for reward, to inhibit an already initiated response, and to estimate the passage of time. These processes have been found to be important to the understanding of impulsive behaviors. The programs are flexible and allow the experimenter to manipulate a number of parameters related to delay-reward contingencies, timing, performance feedback/payment, and data output variables. Manipulation of these parameters makes the paradigms scalable to a wide range of ability levels and appropriate for samples ranging from children to adults. The four paradigms in this software package are available at no cost and can be obtained by contacting the corresponding author.     

Synchronizing programs using Macromedia Director plug-ins: An example from the field of developmental psychopathology

Synchronizing the display of a stimulus with physiological recording or subjects’ behavioral responses is crucial for acquiring valid measures of performance. This article describes a technique for integrating the presentation of stimuli, behavior reports, and physiological data employing Macromedia Director and a standard biometric program using an example from the field of developmental psychopathology. Our experience has been that the use of this technique is effective in creating complex protocols for research. Although the temporal accuracy available from this particular method is adequate for some experiments, it is not suited for investigations requiring single millisecond accuracy. Considerations and suggestions for utilizing this and similar techniques for integrating data collection and stimuli presentation are discussed.