![]() ![]() ![]() The N-back and the Sternberg Item Recognition tasks were also used for such purposes. Increasing the cognitive load in WM mostly happened by increasing the number of items (alphabets, digits, or images) to encode or retrieve, or by changing the order of items to be encoded from sequential to random, to make it more difficult. There are numerous fMRI studies performed on the modulation of cognitive load in working memory (WM), but only rare studies in LTM, as briefly reviewed in below. There are reports on the retrieval process being unaffected in higher demands (e.g., concurrent task performance) ( Peterson and Zill, 1986 Naveh-Benjamin et al., 2000), whereas the impairment of memory retrieval in such situations is also reported ( Jacoby, 1991 Moscovitch, 1992). As an example, when reading a word in a sentence, its meaning comes from our LTM however, this process is more demanding when reading verbal compounds, or when reading multiple words in a syntactic structure ( McIntyre, 2007). This retrieval usually happens without intention and is able to survive at complex situations, such as when performing several tasks at once ( Fischer et al., 2007). In everyday life, retrieving information from memory, and particularly Long-Term Memory (LTM), in order to perform the given tasks is essential. Cognitive demand, or as is more often called “cognitive load,” refers to the amount of information the brain simultaneously processes. The muscles of the body work harder in a more demanding situation, such as when lifting a heavier weight this process could be used as a metaphor to suggest what happens in our brain during a cognitive load. Memory is essential for many cognitive abilities of the human ( Batouli and Sisakhti, 2019), and therefore a clear understanding of the mechanism of human memory is vital ( Batouli et al., 2020). The findings of this study revealed that the mechanism by which a difficult-to-retrieve memory is handled is mainly by elevating the activation of the responsible brain areas and not by getting other brain regions involved, which is a help to better understand the LTM retrieval process in the human brain. Some structures showed reduced activation when retrieving higher load images, such as the anterior cingulate, insula, and supramarginal and postcentral gyri. parahippocampus, cerebellum, superior lateral occipital, fusiform and lingual gyri, precuneus, and posterior cingulate gyrus. We observed seven brain structures showing the highest activation with increasing load of the retrieved images, viz. The participants had to retrieve these previously memorized images during the fMRI scan in 15 s, with their eyes closed. Behavioral assessments on a separate group of participants (#22) provided the average loads of the images. The images were of 12 categories relevant to daily events, with each category including a high and a low load image. We asked 32 healthy young volunteers to memorize all possible details of 24 images over a 12-day period ending 2 days before the fMRI scan. Despite numerous studies about the effect of cognitive loads on working memory processes, whether these can be applied to long-term memory processes is unclear. Identifying the brain structures which manage this increasing cognitive demand would enhance our knowledge of human memory. One of the less well-understood aspects of memory function is the mechanism by which the brain responds to an increasing load of memory, either during encoding or retrieval. ![]() 4Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.3Centre for Healthy Brain Aging (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.2Neuroimaging and Analysis Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran.1Institute for Cognitive Sciences Studies, Tehran, Iran.Sachdev 3† and Seyed Amir Hossein Batouli 2,4*† ![]()
0 Comments
Leave a Reply. |