Aspects of memory in 76 patients, 64 of whom had undergone unilateral temporal lobectomy, were studied. The first two experiments examined whether recognition and recall in patients with these lesions varied as a function of cognitive operations known to influence memory in normal subjects. Experiment 1 examined incidental verbal recall and recognition as a function of prior decisions concerning either the physical, phonemic or semantic features of words. Experiment 2 examined face recognition as a function of either previous sex-discrimination judgments or previous judgments about the likeableness of photographed faces. In verbal recall and recognition the left temporal-lobe patients followed the pattern of normal subjects in benefiting from semantic encoding, thus failing to lend support to the hypothesis that an impairment in semantic organization is a significant causal factor in the memory deficit. In contrast patients with left temporal-lobe lesions failed to benefit in verbal recall from having made phonemic decisions and likewise patients with right temporal-lobe lesions failed to profit in the face recognition task from having made likeableness decisions. These findings suggest that specific impairments in the utilization of certain stimulus features do contribute to the observed memory impairments.; The dissociation between the influence of semantic and phonemic analysis on recall after left temporal lobectomy was interpreted as providing further evidence, consistent with that derived from aphasic patients, that the process of linguistic analysis is divisible into systems that are concerned with phonemic representations and those that are concerned with semantic aspects of words. This dissociation also suggests that left temporal-lobe structures are more highly specialized for the evocation of the sound of a word than for those processes underlying the recall of semantically encoded items.; Part II explored the transmodal generalizability of previous work in vision that had implicated the hippocampal region of the right hemisphere in the recall of spatial location. This was achieved by assessing the recall of information specifying spatial location derived from active touch. Blindfolded subjects were required to reproduce the location of a pin within the area defined by a circle after a delay of either 12 or 24 sec. All groups performed normally at the 12 sec delay, demonstrating accurate registration of simple spatial information even after extensive removal of the right hippocampal area. Impairment after 24 sec was found in patients with right temporal lobectomy that included radical excision of the hippocampal region but was seen only on the left hand (i.e., the hand contralateral to the lesion). These results extend evidence of the functional role of the right hippocampal region in the recall of spatial location to the recall of such information derived from active touch, thus providing further support for the notion that the processing of spatial information is organized intermodally, rather than along modality-specific lines. The confinement of the impairment to the hand contralateral to the lesion suggests that the right and left hippocampal regions differ in their functional relationships to cerebral areas subserving primary somatosensory function.
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