Accelerated Long-Term Forgetting Limited to the Recollection Component of Recognition Memory in a Temporal Lobe Epileptic Patient

Accelerated long-term forgetting: Design and validation of a neuropsychological tool in healthy subjects and diagnostic accuracy in a group of subjects with severe acquired brain injury

OBJECTIVE

Accelerated Long-term Forgetting (ALF) is a phenomenon characterized by abnormal memory forgetting over hours or days, despite normal initial acquisition. Because standardized memory assessments typically test memory retention over delays of up to 30 minutes, ALF may be undetected.

METHODS

The first Experiment of the present study was aimed to validate, in a sample of healthy subjects (n = 54, 20 to 79 years old), a long-term verbal and visuospatial memory procedure, using common tests but administered at extended intervals. In Experiment 2, we aimed to explore ALF pattern in a sample of patients with severe Acquired Brain Injury (sABI) who subjectively complained of memory difficulties and nevertheless obtained normal or only mildly deficient scores on traditional memory tasks (n = 10).

RESULTS

Results of Experiment 1 showed that both the verbal and visuo-spatial memory tasks proved to be valid and effective at illustrating the phenomenon of forgetting along the time intervals considered. Moreover, a significant association was found between higher saving scores passing from the 30 min to the 24 hr interval of the verbal test and the score obtained on a questionnaire assessing the subjective feeling of memory functioning. Results of Experiment 2 showed that patients with sABI obtained reduced 30 m-24hr saving scores on the verbal test as compared to healthy controls despite comparable forgetting at earlier and later delays.

CONCLUSIONS

These findings support the utility of extended memory assessment, thus the need for validation of specific diagnostic tools in clinical practice.

Early detection of memory impairments in older adults: standardization of a short version of the verbal and nonverbal Recognition Memory Test

In several neurological conditions, in elderly and cognitively impaired subjects, memory functioning must be evaluated to early detect the cognitive deterioration processes. In particular, recognition memory assessment is an essential step in the clinical and neuropsychological evaluation of early memory impairments. The Recognition Memory Test (RMT) developed by Smirni et al. (G Ital Psicol XXXVII(1):325-343, 2010) is an effective instrument to assess verbal and nonverbal recognition memory in the Italian population. The current study provides a new, brief, and reliable RMT format to evaluate recognition memory on elderly subjects and it reports normative data in an older adult Italian population sample (including 100 participants well distributed across sex, education, and age categories). The shortened version of RMT keeps the administration procedures and materials of the original Italian RMT constant, i.e., words, faces, and buildings. Multiple regression analysis revealed significant effects of age and educational level on performance but no effect of sex. Inferential cutoffs have been determined and equivalent scores computed. The availability of equivalent scores for the Recognition Memory Test will prove useful in the clinical evaluation of patients' memory profiles.