Age-related changes in the functional neuroanatomy of overt speech production

Abstract

Alterations of existing neural networks during healthy aging, resulting in behavioral deficits and changes in brain activity, have been described for cognitive, motor, and sensory functions. To investigate age-related changes in the neural circuitry underlying overt non-lexical speech production, functional MRI was performed in 14 healthy younger (21-32 years) and 14 healthy older individuals (62-84 years). The experimental task involved the acoustically cued overt production of the vowel /a/ and the polysyllabic utterance /pataka/. In younger and older individuals, overt speech production was associated with the activation of a widespread articulophonological network, including the primary motor cortex, the supplementary motor area, the cingulate motor areas, and the posterior superior temporal cortex, similar in the /a/ and /pataka/ condition. An analysis of variance with the factors age and condition revealed a significant main effect of age. Irrespective of the experimental condition, significantly greater activation was found in the bilateral posterior superior temporal cortex, the posterior temporal plane, and the transverse temporal gyri in younger compared to older individuals. Significantly greater activation was found in the bilateral middle temporal gyri, medial frontal gyri, middle frontal gyri, and inferior frontal gyri in older vs. younger individuals. The analysis of variance did not reveal a significant main effect of condition and no significant interaction of age and condition. These results suggest a

A synopsis on aging—Theories, mechanisms and future prospects

“…While generally appreciated, there is a pop culture that is youth-oriented, we look to preserve our younger self, resorting to a wide variety of hyped age-delaying crèmes, and, when picturing older people, we often think of people who are physically and/or mentally slower and TV programs do little to contradict such stereotypes (Lee et al, 2007). Yet, there are definite alterations that we can evaluate, such as those observed in the functional neuroanatomy that induce alterations in overt speech production (Soros et al, 2011). In Table 4, some of these quantifiable variations are listed.…”

Impact of changed positive and negative task-related brain activity on word-retrieval in aging

“…Modern imaging techniques like functional magnetic resonance imaging (fMRI) can help to unravel the mechanisms associated with healthy or pathological aging (for a review see Crosson et al, 2010). However, even though a large number of studies used functional imaging techniques to compare activity patterns associated with memory, attentional or perceptual processes in younger and older adults (Park and Reuter-Lorenz, 2009), very few studies so far have addressed language production mechanisms (Wierenga et al, 2008; Sörös et al, 2009; Meinzer et al, 2009; Shafto et al, 2010). This is of interest as word-retrieval deficits are frequently observed even in healthy older adults (Burke and Shafto, 2004) and constitute an early symptom of dementia (Henry, 2004).…”

Functional and structural aging of the speech sensorimotor neural system: functional magnetic resonance imaging evidence

“…One fMRI study has examined age-related neural changes in overt speech production (Soros et al, 2011) and found increased activation in several areas in elderly compared to young adults, including A1, the ventral premotor cortex (PMv), the supplementary motor area (SMA-proper) and the prefrontal cortex. There was also decreased activation in posterior supratemporal areas including STG.…”