Does visuo-spatial working memory generally contribute to immediate serial letter recall?

This work contributes to the understanding of the visual similarity effect in verbal working memory, a finding that suggests that the visuo-spatial sketch pad-the system in Baddeley's working memory model specialised in retaining nonverbal visual information-might be involved in the retention of visually presented verbal materials. Crucially this effect is implicitly interpreted by the most influential theory of multimedia learning as evidence for an obligatory involvement of the visuo-spatial sketch pad. We claim that it is only involved when the functioning of the working memory component normally used for processing verbal material is impaired. In this article we review the studies that give rise to the idea of obligatory involvement of the visuo-spatial sketch pad and suggest that some findings can be understood with reference to orthographic rather than visual similarity. We then test an alternative explanation of the finding that is most apt to serve as evidence for obligatory involvement of the visuo-spatial sketch pad. We conclude that, in healthy adults and under normal learning conditions, the visual similarity effect can be explained within the framework of verbal working memory proposed by Baddeley (e.g., 1986, 2000) without additional premises regarding the visuo-spatial sketch.

Development of a test device for evaluation of thrown object hazards.

High-speed chains or rotating disks are commonly used to cut and process trees during forest harvesting operations. Mechanical failure or fatigue of these tools can lead to a potentially hazardous situation where fragments of chain or sawteeth are thrown through the operator enclosures on forest machines. Therefore, a test device is needed to evaluate the ability of a forest machine cab to resist puncture by thrown objects. This articles details the development of a high-pressure pneumatic launch system that propels sawteeth and chain fragments at velocities in excess of 150 m/s. This article also discusses the performance of the device following the first series of projectile launches.

Documentation of hazards and safety perceptions for mechanized logging operations in East Central Alabama.

The logging industry remains one of the most hazardous in the nation. Despite more stringent safety regulations and improvements in equipment safety features, the rate of logging fatalities has decreased at a much lower rate than the decrease in the rate of illnesses and injuries in the same occupation. The objective of this research was to identify and assess the hazards associated with logging operations in the Southeast region of the U.S. and propose interventions, taking into consideration the fact that, currently, most operations in the region are fully mechanized. Five logging crews in East Central Alabama participated in the study and were observed repeatedly during their normal operations. Researchers observed loggers engaging in multiple unsafe behaviors, but none of those led to an injury. The incidence of unsafe behaviors may be due in part to a lack of awareness of the hazards. Results indicate that Occupational Safety and Health Administration (OSHA) regulations appear to have little influence on logging safety. Loggers believe that most safety training recommendations are difficult to implement and negatively impact productivity. Thus, there seem to be fundamental drawbacks in the logging industry regarding effective delivery of safety training to loggers. The present study was a joint venture by the Industrial and Systems Engineering and Psychology departments of Auburn University, with support from the United States Forest Service (USFS).

Identification and characterization of proteins that interact with Drosophila melanogaster protein kinase CK2.

D. melanogaster CK2 (DmCK2) is a highly conserved protein kinase that is composed of catalytic, alpha, and regulatory, beta, subunits associated as an alpha2beta2 heterotetramer. In order to analyze the functions of CK2 in this metazoan model, we have used the two hybrid approach to identify interacting proteins. One of these cDNAs, DmA24, encodes a novel polypeptide with no homologs in GenBank, and is notable in that it contains a bipartite nuclear localization signal and two sites for phosphorylation by CK2. In situ hybridization to polytene chromosomes indicates that the DmA24 gene is located at the 61 D interval of chromosome II a region that also harbors 3 additional genes with similar structure. DmA24p interacts with DmCK2alpha, but not with DmCK2beta, demonstrating that this interaction is specific for the catalytic subunit of CK2. In addition, the protein is phosphorylated by the holoenzyme purified from Drosophila embryos. These studies identify DmA24p as a potentially new physiological partner of DmCK2. In addition, we also report the results of a large-scale screen that has identified a new set of DmCK2-interacting proteins. Most notable among these are Surf6, a nucleolar protein involved in RNA processing, and Spalt, a homeotic protein.

[Phonological information in short-term memory of sentences]. / Phonologische Information beim kurzfristigen Behalten von Sätzen.

Potter and Lombardi (1990) showed that words that are semantically similar to nouns of auditorily or visually presented sentences intrude into sentence recall if presented in an unrelated word list (given either before or after the sentence). The authors interpreted this finding in terms of the conceptual regeneration hypothesis. This hypothesis states that sentence recall is based on conceptual information whereas the role of phonological information is negligible. However, this general interpretation is questionable. In order to demonstrate the involvement of phonological information in sentence recall, we used Potter and Lombardi's intrusion paradigm. Participants were either presented with auditory or visual material. With respect to visual presentations we used two conditions: a rapid presentation rate (rapid serial visual presentation, RSVP) and a slow presentation rate. Under all conditions the word list was presented before the sentence. The intrusion effect was only found for RSVP but not for the slow conditions. This finding provides evidence for the assumption that phonological information generally plays an important role in short-term sentence recall.

[Control processes in speech production: flexibility and determination of event related speech planning]. / Kontrollprozesse beim Sprechen: Flexibilität und Determination der ereignisbezogenen Ausserungsplanung.

The issue of our study is the flexibility of high level adjustments for the process of relating events. Our assumptions are based on the Mannheim Regulation Theory of Speech Production, in which three modes of central control are distinguished: stimulus control, schema control, and ad hoc control. Our first experiment shows that verbal accounts of an event (due to selection and construction processes) as well as the interindividual variability of this accounts (due to the control mode being less or more restricted) are strongly determined by the situational characteristics in which they are produced. In our second experiment, pressure of time is introduced into the speech production task as a disturbance factor to put some load on the attentional resources thus uncovering the flexibility vs. automaticity of the speech production process. A comparison of the results favors the assumption of verbal accounts of an event being produced by strong schematic control in a highly institutionalized situation, whereas verbal accounts of the same event in an unofficial, private situation are produced by more ad hoc planning. The results permit to psychologically reconstruct the narrating of events and the reporting of events as speech production processes which are guided by different control modes with respect to their flexibility and to their attentional demands.