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Abstract:
Abstract: Estrogen reportedly influences paired associate
recall but not visual memory, digit span or paragraph recall
(Phillips & Sherwin, 1992). These findings suggest that hormone
fluctuations selectively influence memory abilities involved in
'association formation' but not other (unspecified) memory
processes. In our own studies of estrogen fluctuations across the
menstrual cycle (Collier & Shulman, 1995, 1998) we reached a
different view of which cognitive functions are influenced by
estrogen fluctuations. At high estrogen levels we found superior
procedural learning (mirror reading task), but not declarative
memory (word recall). We also reported that performance on a
context switching task was superior at high estrogen levels and
argued that the common element in procedural learning and context
switching may be the basal ganglia, which are rich in estrogen
receptors (Majewska, 1992). In addition to procedural learning, the
basal ganglia also may play a role in contextual control of
response selection and inhibition of inappropriate response sets
(Hayes et al., 1998), such as our context switching task. We
pursued this reasoning by testing post menopausal women either
treated or not with Hormone Replacement Therapy (HRT). To test
procedural learning we administered the Tower of Hanoi problem.
Contextual control over response selection was assessed using a
context switching task in which two conflicting response rules were
intermixed in a series of trials. Results showed superior
performance by HRT subjects, supporting the hypothesis of basal
ganglia involvement.
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