Aging and the lateralization of oscillatory activities related to external and internal motor preparation

Selection of action may rely on external guidance or be motivated internally, engaging partially distinct cerebral networks. With age, there is an increased allocation of sensorimotor processing resources, accompanied by a reduced differentiation between the two networks of action selection. The present study examines the age effects on the motor-related oscillatory patterns related to the preparation of externally and internally guided movements. Thirty-two older and 30 younger adults underwent three delayed motor tasks with S1 as preparatory and S2 as imperative cue: Full, laterality instructed by S1 (external guidance); Free, laterality freely selected (internal guidance); None, laterality instructed by S2 (no preparation). Electroencephalogram (EEG) was recorded using 64 surface electrodes. Motor-Related Amplitude Asymmetries (MRAA), indexing the lateralization of oscillatory activities, were analyzed within the S1-S2 interval in the mu (9-12 Hz) and low beta (15-20 Hz) motor-related frequency bands. Reaction times to S2 were slower in older than younger subjects, and slower in the Free than in the Full condition in older subjects only. In the Full condition, there were significant mu MRAA in both age groups, and significant low beta MRAA only in older adults. The Free condition was associated with large mu MRAA in younger adults and limited low beta MRAA in older adults. In younger subjects, the lateralization of mu activity in both Full and Free conditions indicated effective external and internal motor preparation. In older subjects, external motor preparation was associated with lateralization of low beta in addition with mu activity, compatible with an increase of motor-related resources. In contrast, absence of mu and limited low beta lateralization in internal motor preparation was concomitant with reaction time slowing and suggested less efficient cerebral processes subtending free movement selection in older adults, indicating reduced capacity for internally driven action with age.

SNTL:n Korkeimman neuvoston puhemiehistön puheenjohtajan N.V. Podgornyin virallinen vierailu Suomeen 14.-18.10.1969 (Tasavallan Presidentin vastauspuhe Neuvostoliiton suurlähetystössä SNTL:n Korkeimman neuvoston puhemiehistön puheenjohtaja N.V. Podgornyin vierailun johdosta järjestetyillä päivällisillä 15.10.1969)

Puhe

Itävallan liittopresidentti Rudolf Kirchslägerin virallinen vierailu Suomeen 15.-18.3.1977 (Tasavallan Presidentin maljapuhe Itävallan liittopresidentti ja rouva Kirchschlägerin tarjoamilla juhlapäivällisillä Kalastajatorpalla 16.3.1977)

Puhe

Mikkeli 15.6.1929

Kirje

Audit report on a special investigation of the City of Gravity for the period January 1, 2003 through February 15, 2007

Audit report on a special investigation of the City of Gravity for the period January 1, 2003 through February 15, 2007

Olli Poroila 15/12 1975

Kirje 15.12.1975

[Helsinki] 15 p:nä kesäkuuta 1942

Kirje 15.6.1942

Desenvolvimento pós-embrionário de Pattonella intermutans (Thomson) (Diptera: Sarcophagidae) em diferentes dietas

A proposta deste estudo foi de avaliar o desenvolvimento pós-embrionário de Pattonella intermutans (Thomson, 1869) em dietas artificiais preparadas com agar-agar. Dieta D1: leite em pó integral + fermento biológico; Dieta D2: leite em pó integral + fermento biológico + caseína; Dieta D3: leite em pó integral + ovo cru; Dieta D4: carne bovina moída (dieta controle). A carne bovina moída foi a dieta mais eficiente (peso larval de 195,63 mg e viabilidade de neolarva a adulto de 86,5%), quando comparada com as dietas artificiais. Os seguintes resultados foram obtidos para o grupo experimental: Dieta D3: 180,15 mg e 63,5%; Dieta D2: 141,07 mg e 61% e na Dieta D1: 147,98 mg e 51,5%.

Akateemikko Rolf Nevanlinna 15/12 1964

Kirje 15.12.1964

Iowa Lottery Action, April 2-15, 2007, Vol. 14, no. 7.

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