Repeated measurements analysis of variance when the correlations have a certain pattern

Consider a repeated measurements study in which a single observation is taken at each oft(t > 2) equally spaced time points for each ofn subjects. This paper uses a result of Box to find the appropriate multiplicative correction term for the degrees of freedom in the analysis of variance table for the case when there is equal variability per time point, and when the correlation between observationsu time units apart is equal to ^u . For large values oft, the multiplicative correction has a lower bound approximately equal to 2.5/(t – 1).Dr. Fleiss is also with the Biometrics Research Unit of the New York State Psychiatric Institute. This work was supported in part by grant DE 04068 from the National Institute of Dental Research.     

Intrahippocampal scopolamine impairs both acquisition and consolidation of contextual fear conditioning

Lesions of the dorsal hippocampus have been shown to disrupt both the acquisition and the consolidation of memories associated with contextual fear (fear of the place of conditioning), but do not affect fear conditioning to discrete cues (e.g., a tone). Blockade of central muscarinic cholinergic receptor activation results in selective acquisition deficits of contextual fear conditioning, but reportedly has little effect on consolidation. Here we show for the first time that direct infusion of the muscarinic cholinergic receptor antagonist, scopolamine, into the dorsal hippocampus produces a dose-dependent deficit in both acquisition and consolidation of contextual fear conditioning, while having no impact on simple tone conditioning.