Temporal and parietal association cortex lesions and spatial and black-white reversal learning in the rat

Abstract

In Experiment 1, rats with parietal, temporal, or frontopolar neocortex ablations and nonoperated controls were trained on seven spatial reversals. The animals with parietal association cortex damage were found to be deficient on this task compared to all other groups. In Experiment 2, rats with either temporal or striate neocortical ablations or subcortical lesions of the lateroposterior thalamic nucleus and nonoperated controls were trained on a black-white reversal task. The rats with temporal damage committed significantly more errors than all other groups. These results together with those of previous research suggest that a dissociation exists between the effects of parietal and temporal association cortex ablations on reversal learning in the rat. It was suggested that the visual functions of the temporal association cortex might be mediated by connections with either the striate cortex or the lateroposterior thalamic nucleus.

Posterior association cortex and visual pattern discrimination in the rat

“…These findings, taken with those from previous studies (Boyd & Thomas, 1977;McDaniel & Thomas, 1978;, indicate that a clear dissociation exists between the effects of lesions within the parietal and temporal association cortices in the rat. Lesions of the parietal association cortex appear mainly to disrupt learning dependent upon the use of spatial cues.…”

“…Clean surgical techniques were used. After a midline incision was made and the dorsal cranium' exposed, the skull was drilled with a trephine of the size and at the coordinates used by McDaniel and Thomas (1978). After the underlying cortical matter was aspirated, the scalp was sutured.…”

“…The apparatus was the same as the two-choice alley previously described by McDaniel and Thomas (1978) and consisted of a startbox, a choice arena, and two parallel goal boxes. The startand goalboxes were constructed to be interchangeable, with the rear wall constructed of Plexiglas.…”

“…The positions of the correct stimuli were randomized according to a Gellerman series (1933). Criterion for learning consisted of the animal scoring at least 80% correct responses on 2 consecutive days, and the animals were trained using a correction procedure previously described (Boyd & Thomas, 1977;McDaniel & Thomas, 1978;Snyder & Diamond, 1968). A ceiling of twice the number of trials required by the first two-thirds of the animals to reach criterion was used.…”

“…This view receives further credence from several neurophysiological studies that have demonstrated that the activity of neurons in the parietal association cortex is associated with several visuo-attentional mechanisms in rhesus macaques (Mountcastle, 1976) and cats (Robertson, 1976;Robertson, Mayers, Teyler, Bettinger, Birch, Davis, Phillips, & Thompson, 1975). Because of the close anatomical relationship between the temporal region and striate cortex (Montero, Bravo, & Fernandez, 1973) and the lateroposterior thalamic nucleus (Hughes, 1977;McDaniel et al, 1978), it might be argued that the temporal deficit represents an impairment of visual information processing mechanisms. The present experiment was designed to compare rats with either parietal or temporal association cortex lesions on the acquisition of a complex visual pattern discrimination.…”