The Simon effect and visual motion

Summary S-R compatibility and Simon effects were studied for real visual motion. In Experiment 1, two small stimulus lights were constantly visible, 5° to the left and right of fixation; after a random delay, one began to move at 2°/s. In Experiment 2, a single stimulus light moving at 2°/s suddenly appeared 5° to the left or right of fixation, i. e., motion onset and stimulus onset coincided. In both experiments, subjects responded by a key press with their left or right index finger as soon as they detected motion. In Condition A responses were made to the position (left or right) from which the motion started, irrespective of its direction (position compatibility); in Condition B responses were made to the direction of motion (leftward or rightward) irrespective of whether motion started to the left or to the right of fixation (direction compatibility). The results show strong compatibility effects for both position and direction of motion in both experiments. A Simon effect, however, occurred only when position was task irrelevant in Experiment 1; no Simon effect was found in Experiment 2. The data only partly confirm previous results obtained with apparent motion. The selective lack of a Simon effect supports the integrated model of Umiltá and Nicoletti (1992), which requires orienting of attention for the Simon effect to occur. It is specifically assumed that this attention-orienting is triggered only by the saccade program and does not extend to the pursuit program that is initiated by smooth stimulus motion.     

The Effect of an Irrelevant Premise on Temporal and Spatial Reasoning

The mental model theory of reasoning postulates that individuals reason by constructing models of the situation described by premises. The more models reasoners have to build, the harder a problem will be. Byrne and Johnson-Laird (1989) confirmed this prediction with spatial problems and Schaeken et al. (1996 a, b) with temporal ones. There is, however, a problem with these studies. All the multiple-model problems and some of the one-model problems contained an irrelevant premise. As Rips (1994) argues, it is possible that an irrelevant premise would complicate the search for a derivation. The present paper reports an experiment which explicitly manipulated the presence of such an irrelevant premise in both one-model and multiple-model problems. The results corroborate the predictions of the mental model theory.     

A powerful,inexpensive experiment controller or IBM PC interface and experiment control language

A very powerful, but inexpensive, advanced technology (16 MHz 80C188EB) experiment controller is described. It can be programmed in either a BASIC-like (ECBASIC) or an ALGOL-like (ECL) procedure specification language. It provides 1-msec resolution, optional transparent total data logging, and is designed to function as a remote peripheral processor in a network with virtually any computer acting as the network supervisor (e.g., IBM compatible or Macintosh). Each serial port on the host computer can support up to 10 simultaneous experiments. The various optional I/O modules provide for opto-isolated normally open or normally closed switch operation input, high current output, as well as D/A and A/D functions. Our I/O modules can also be plugged directly into an IBM PC parallel port by using a small adaptor board. In this way, the advantages of using ECBASIC or ECL to control experiments are available to researchers who wish to simply interface their host computer directly to the apparatus in order to minimize expense.     

Spatial orientation by mental transformation

Across three experiments, college students read narratives describing two-dimensional horizontal, sagittal, or coronal environments, each with seven objects in surrounding directions (at 45° angles). Then they responded from memory to questions about which objects were in specific directions. The distributions of error rates and response times were compared with distributions predicted by a mental transformation model and two verbal-spatial decoding and retrieval models. The data fit the predictions of a modified mental transformation model (mental transformation plus 180° exception) better than the predictions of either verbal-spatial model. This was true even though the environment was presented narratively rather than perceptually, and it was true for both the vertical planes in addition to the more typical horizontal plane. Received: 8 August 1997 / Accepted: 2 June 1998     

Content Analysis of the Journal of Counseling & Development: Volumes 67 to 74

This study examined the content of the Journal of Counseling & Development. Collected data were used to identify various changes and trends over time. A content analysis was conducted for a 9-year period (Volumes 67–74). Articles were cross-classified into 11 categories of topics with 7 subcategories and then grouped by the 3 editorship periods during this time. Topics were then evaluated and ranked for each editorship to identify possible trends. An overall ranking of topics is provided, as well as rankings of contributing authors, institutional affiliations, and states represented by contributing authors. Results are compared with an earlier content analysis (Pelsma & Cesari, 1989) of Volumes 48 to 66.     

MMPI-2 Assessment of Varying Levels of Posttraumatic Stress in Vietnam Combat Veterans

The effectiveness of the MMPI-2 in the detection of posttraumatic stress (PTS) symptomatology was investigated. Forty-nine veterans at a VA posttraumatic stress clinic were evaluated for PTS symptomatology according to DSM-III-R criteria. The ability of the MMPI-2 to differentiate between Vietnam combat veterans (VCV) who met DSM-III-R criteria for posttraumatic stress disorder (PTSD; N = 36) and those who reported varying levels of posttraumatic stress symptoms (PTSS; N = 13) was examined. Overall, the MMPI-2 was effective in differentiating between the two groups of veterans. Of the 15 MMPI-2 scales used to evaluate PTS symptomatology, 12 significantly differentiated veterans with PTSD from those with PTSS. Diagnostic efficiency statistics for the MMPI-2 PTSD scales (PS and PK) were calculated at four cutoff points (T 65, 70, 75, and 80). The PS Scale was the most robust and effective index in differentiating between veterans with PTSD and those with PTSS. Implications for the assessment of varying degrees of PTS are discussed.     

Listener response to stuttering modification techniques

In two investigations, nonprofessional listeners used a 25-item bi-polar adjective scale to evaluate an adult male speaker who stuttered. In investigation one, 24 listeners evaluated the speaker during a Stuttering Only and a Stuttering + Cancellation condition. In investigation two, 50 listeners evaluated the speaker in a Stuttering Only and a Stuttering + Pullout condition. Listeners in the first investigation did not assign significantly different ratings to the Stuttering Only and Stuttering + Cancellation conditions. In the second investigation listeners rated the Stuttering Only condition more positively than the Stuttering + Pullout condition (p < 0.05). Analysis of listener response to four open-ended questions indicated significantly more positive reaction to the Stuttering Only condition than either of the Stuttering + Modification conditions. Finally, listeners rated the speaker using the cancellation and pullout techniques as being significantly more handicapped than when he was stuttering only. The findings provided preliminary evidence indicating that everyday listeners may react less favorably to an adult male speaker who is modifying his stuttered speech than when this same speaker is simply stuttering.