Biomedical subjects

Angela H Gutchess

Publications and source records attributed to Angela H Gutchess.

7 recordsLinked to original sources

PubMed2006

fMRI environment can impair memory performance in young and elderly adults.

The influence of the fMRI (functional magnetic resonance imaging) scanning environment on working memory and long-term memory performance was investigated. We predicted that performance would be impaired on memory tasks in the distracting fMRI environment relative to laboratory performance. Results indicated that both young and old adults showed performance decrements in the scanning environment compared to the laboratory for a long-term memory task, but not for a passive working memory task, consistent with the idea that divided attention costs occur for more difficult tasks. In addition, elderly adults were disproportionately impaired by the scanning environment on the long-term memory task, congruent with the finding that divided attention costs at encoding are larger for older than younger adults. The findings suggest that performance may be changed by the scanning environment and that, in some circumstances, the fMRI environment may have a disproportionate effect on cognitive performance of older adults.

Adult↗

PubMed2006

Pictorial naming specificity across ages and cultures: a latent class analysis of picture norms for younger and older Americans and Chinese.

BACKGROUND: Cognitive aging research, as well as cross-cultural research, often relies on pictorial stimuli to address how perceptions of common objects vary by population group. OBJECTIVE: We investigate naming specificity--the degree of detail elicited for object labels - across age (younger-older) and culture (American-Chinese). METHODS: Using latent class analysis techniques, we segregated picture-item responses into multiple specificity levels. The analysis was conducted for 260 pictures, across four groups of younger (aged 17-25 years) and older (aged 59-76 years) adults in the US and mainland China. RESULTS: Overall, three naming specificity classes were supported. Age differences were modest compared to those across culture. In particular, Chinese groups showed far greater variation, naming more items both with high and with low specificity than age-matched American counterparts. Our results differed from prior studies using familiarity and latency measures. Moreover, approximately 28% of commonly-used picture items differed across all four groups. CONCLUSION: These results highlight the need to select appropriate pictorial stimuli for studies involving populations diverse in age and cultural background.

Adolescent↗

PubMed2006

Categorical organization in free recall across culture and age.

BACKGROUND: Cross-cultural differences in cognition suggest that Westerners use categories more than Easterners, but these differences have only been investigated in young adults. OBJECTIVE: The contributions of cognitive resource and the extent of cultural exposure are explored for free recall by investigating cross-cultural differences in categorical organization in younger and older adults. Cultural differences in the use of categories should be larger for elderly than young because categorization is a well-practiced strategy for Westerners, but age-related cognitive resource limitations may make the strategy difficult for elderly Easterners to implement. Therefore, we expect that cultural differences in categorization will be magnified in elderly adults relative to younger adults, with Americans categorizing more than Chinese. METHODS: Across two studies, 112 young and 112 elderly drawn from two cultures (American and Chinese) encoded words presented in their native language. One word list contained categorically-unrelated words and the other, categorically-related words; both lists were presented in the participants' native language. In experiment 1, the words were strong category associates, and in experiment 2, the words were weak category associates. Participants recalled all the words they could remember, and the number of words recalled and degree of clustering by category were analyzed. RESULTS: As predicted, cultural differences emerged for the elderly, with East-Asians using categories less than Americans during recall of highly-associated category exemplars (experiment 1). For recall of low-associate exemplars, East-Asians overall categorized less than Americans (experiment 2). Surprisingly, these differences in the use of categories did not lead to cultural differences in the number of words recalled. The expected effects of age were apparent with elderly recalling less than young, but in contrast to previous studies, elderly also categorized less than young. CONCLUSION: These studies provide support for the notion that cultural differences in categorical organization are larger for elderly adults than young, although culture did not impact the amount recalled. These data suggest that culture and age interact to influence cognition.

Adolescent↗

PubMed2006

Cultural differences in neural function associated with object processing.

Behavioral research suggests that Westerners focus more on objects, whereas East Asians attend more to relationships and contexts. We evaluated the neural basis for these cultural differences in an event-related fMRI study. East Asian and American participants incidentally encoded pictures of (1) a target object alone, (2) a background scene with no discernable target object, and (3) a distinct target object against a meaningful background. Americans, relative to East Asians, activated more regions implicated in object processing, including bilateral middle temporal gyrus, left superior parietal/angular gyrus, and right superior temporal/supramarginal gyrus. In contrast to the cultural differences in object-processing areas, few differences emerged in background-processing regions. These results suggest that cultural experiences subtly direct neuralactivity, particularly for focal objects, at an early stage of scene encoding.

Adolescent↗

PubMed2005

Aging and the neural correlates of successful picture encoding: frontal activations compensate for decreased medial-temporal activity.

We investigated the hypothesis that increased prefrontal activations in older adults are compensatory for decreases in medial-temporal activations that occur with age. Because scene encoding engages both hippocampal and prefrontal sites, we examined incidental encoding of scenes by 14 young and 13 older adults in a subsequent memory paradigm using functional magnetic resonance imaging (fMRI). Behavioral results indicated that there were equivalent numbers of remembered and forgotten items, which did not vary as a function of age. In an fMRI analysis subtracting forgotten items from remembered items, younger and older adults both activated inferior frontal and lateral occipital regions bilaterally; however, older adults showed less activation than young adults in the left and right parahippocampus and more activation than young adults in the middle frontal cortex. Moreover, correlations between inferior frontal and parahippocampal activity were significantly negative for old but not young, suggesting that those older adults who showed the least engagement of the parahippocampus activated inferior frontal areas the most. Because the analyses included only the unique activations associated with remembered items, these data suggest that prefrontal regions could serve a compensatory role for declines in medial-temporal activations with age.

Adult↗

PubMed2003

Working memory for complex scenes: age differences in frontal and hippocampal activations.

Age differences in frontal and hippocampal activations in working memory were investigated during a maintenance and subsequent probe interval in an event-related fMRI design. Younger and older adults either viewed or maintained photographs of real-world scenes (extended visual or maintenance conditions) over a 4-sec interval before responding to a probe fragment from the studied picture. Behavioral accuracy was largely equivalent across age and conditions on the probe task, but underlying neural activations differed. Younger but not older adults showed increased left anterior hippocampal activations in the extended visual compared with the maintenance condition. On the subsequent probe interval, however, older adults showed more left and right inferior frontal activations than younger adults. The increased frontal activations at probe in older adults may have been compensatory for the decreased hippocampal activations during maintenance, but alternatively could have reflected the increased difficulty of the probe task for the older subjects. Thus, we demonstrate qualitatively different engagement of both frontal and hippocampal structures in older adults in a working memory task, despite behavioral equivalence.

Adult↗

PubMed2002

Aging, cognition, and culture: a neuroscientific perspective.

Behavioral studies have suggested some intriguing differences across cultures in cognitive processes such as attention to context, the use of categorization, stereotypes about aging, and metamemory judgments. Moreover, there is behavioral evidence to suggest that, with age, cultural differences in cognition become less pronounced, likely due to decreased cognitive resources that may result in more similarity across cultures in cognition. The study of the neuroscience of aging, culture and cognition, although in its infancy, potentially provides insight into the contributions of experience and neurobiology to cognitive function. We review initial findings of cross-cultural behavioral aging research in light of cognitive neuroscience of aging research and consider the methodological challenges and benefits of adding a cross-cultural dimension to the study of the cognitive neuroscience of aging.

Aging↗