TY - JOUR T1 - Fornix Lesions Can Facilitate Acquisition of the Transverse Patterning Task: A Challenge for “Configural” Theories of Hippocampal Function JF - The Journal of Neuroscience JO - J. Neurosci. SP - 1622 LP - 1631 DO - 10.1523/JNEUROSCI.18-04-01622.1998 VL - 18 IS - 4 AU - Timothy J. Bussey AU - E. Clea Warburton AU - John P. Aggleton AU - Janice L. Muir Y1 - 1998/02/15 UR - http://www.jneurosci.org/content/18/4/1622.abstract N2 - Configural theories of hippocampal function predict that hippocampal dysfunction should impair acquisition of the transverse patterning task, which involves the concurrent solution of three discrimination problems: A+ versus B−; B+ versus C−; and C+ versus A−. The present study tested this prediction in rats using computer-graphic stimuli presented on a touchscreen. Experiment 1 assessed the effects of fornix lesions when the three problems were introduced sequentially (phase 1: A+ vs B−; phase 2: A+ vs B−, B+ vs C−; phase 3: A+ vs B−, B+ vs C−, C+ vs A−). Fornix lesions significantly facilitated acquisition of the complete transverse patterning task (phase 3) but had no effect on the number of sessions or errors required to attain criterion during phase 1 or phase 2. In experiment 2, in which all three problems were presented concurrently from the outset of training, fornix-lesioned animals outperformed control animals during the seventh block of acquisition trials and were not impaired during any stage of acquisition. Importantly, these same animals were significantly impaired on two allocentric spatial tasks: T-maze alternation (experiments 1 and 2) and the Morris Swim Task (experiment 1). These results contradict the predictions of configural theories of hippocampal function and cast doubt on the popular notion that spatial learning is a special case of configural learning. ER -