[Abstract Title]. - Society for Neuroscience

Abstract: Many experimental memory tasks which are sensitive to hippocampal dysfunction
show a lack of temporal contiguity lasting for more than 100 mseg between event presentations.
At hippocampal CA3 region there is a pattern of recurrent excitatory connections between
pyramidal cells which provides for potential associations within this structure and with the
auditory cortex. Given connections between A1 and hippocampus, it is important to know which
types of auditory short-term mnemonic associations are more appropriate for analysis at CA3
and other hippocampal regions.
Seven patients (5 F, 2 M; ages 10:6 to 16:9) with tumors or vascular malformations of different
temporal regions and their controls (36 F, 29 M; ages 10:2 to 16:9) submitted to a Test of
Frequency Discrimination between tones, a Test of Tonal Memory of 5-tone sequences and a
Test of Pitch Perception of (Spanish) Language segments. Simultaneous cognitive evaluation of
two patients with right or left hippocampal pathology and their personal controls using WISC-R
(Spanish) and Rey‟s test was carried out.
Data obtained point at an involvement of area around A1 in frequency discrimination between
tones. Thus, a subject with a tumor affecting left A1 area connections had marked deficits in
frequency discrimination. Moreover, subjects with tumoral or vascular lesions further away from
A1, or the left operculum and basal nuclei, also manifested low frequency discrimination. On the
other hand, a subject with a right fronto-temporal cyst, a subject with a right posterior cerebral
artery malformation and a subject with a left hippocampal astrocytoma were not affected in
frequency discrimination. However, the two latter subjects, with differing cognitive evaluations
based on results from their psychological testing, were affected in tonal sequence memory.
Interestingly, the younger subjects also showed deficits in perceiving the continuous pitch
deflections of language.
In conclusion, results point at an involvement of the hippocampal area in the association of
complex auditory events in short-term memory of children. Subjects with other temporal
pathology manifesting low or very low performance in frequency discrimination also had low
performance in short-term tonal memory. Hannula & Ranganath (2008) have provided evidence
regarding the importance of the activity of hippocampal structures in short-term relational
memory binding in vision. From the data of the present study, it would appear that similar
relational processes binding pitches in short-term auditory memory may take place in the
hippocampus..
Disclosures: E. Castro-Sierra, None; F. Chico-Ponce de Leon, None; A. Fernandez-Stefano,
None; A. Vargas-Rodriguez, None; S. Martinez-Rodiguez, None.
Poster
288. Working Memory: Disorders, Genes and Connectivity
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 288.7/RR14