Task Consolidation Research Articles

Sequential Training in Separate Paradigms Impairs Second Task Consolidation and Learning-Associated Modulations of Hippocampal NCAM Polysialylation

As transient and time-dependent modulations of neural cell adhesion molecule polysialylation (NCAM PSA) are associated with morphofunctional change and required for the consolidation of spatial and nonspatial forms of learning, we determined the demands imposed on this system by sequential training in the Morris water maze followed by the passive avoidance paradigm. Animals trained in this manner had recall of the water maze but not the passive avoidance response as judged by their escape and avoidance latencies, respectively. Activation of NCAM PSA on dentate neurons at the 12-h post-training time suggested information processing; however, this was significantly less than that predicted for coincident acquisition of both tasks. When sequential training was separated by an interparadigm period of 2 h, an enduring NCAM PSA activation was observed which was indistinguishable from the sum of the expected activations for each individual task. These observations suggest that the NCAM PSA response may become saturated when alternate tasks are presented without an intervening period.

Intrahippocampal Infusion of the NMDA Receptor Antagonist AP5 Impairs Retention of an Inhibitory Avoidance Task: Protection from Impairment by Pretraining or Preexposure to the Task Apparatus

The purpose of the present research was to further evaluate the role of hippocampalN-methyl-d-aspartate (NMDA) receptors in inhibitory avoidance task consolidation. Adult male Wistar rats were trained and tested in a step-down inhibitory avoidance task (0.4 mA footshock, 24 h training–test interval). Immediately after training, animals received a 0.5-μl intrahippocampal infusion of the NMDA receptor antagonist aminophosphonopentanoic acid (AP5) (5.0 μg) or vehicle (phosphate buffer in saline, pH 7.4). The infusion of AP5 impaired retention test performance. Both pretraining with a low footshock intensity (0.2 mA) or preexposure to the inhibitory avoidance box 24 h before training prevented the amnestic effect of AP5. The results suggest that hippocampal NMDA receptors are critical for neither the enhancement of retention induced by an additional training session nor the inhibitory avoidance retention in animals that have previously learned about the task environment by preexposure to the apparatus.

Competing in Information-Intensive Services: Analyzing the Impact of Task Consolidation and Employee Empowerment

:We analyze the competitive and economic implications of information technology, the allocation of decision rights, and task bundling during business process reengineering. The popular reengineering literature advocates employee empowerment—decentralizing decision authority and consolidating tasks—as complementary strategies. Our analysis reveals, however, that implementing these two changes simultaneously is suboptimal in many cases. Decentralization and consolidation decisions can occur separately or together; the optimal combination depends on the effectiveness of technology aimed at skill enhancement and the customers’ sensitivity to time and quality. We identify those process parameters that can cause decentralization and consolidation to have opposite effects on process performance; we also point to other parameters, such as customer-to-customer variability, which can cause them to complement one another. Finally, we explain why, in a time-based competitive marketplace, firms are more likely to centralize their decision-making process while concentrating their information technology investments on enhancing productivity and intraorganizational communications.