Biology subjects

Steinkrauss, A. C.

Publications and source records attributed to Steinkrauss, A. C..

3 recordsLinked to original sources

bioRxiv2022

Neural distinctiveness and discriminability in core network representations support associative unitization

Previous work has suggested unitized pairs behave as a single unit and more critically, are processed neurally different than those of associative memories. The current works examines the neural differences between unitization and non-unitized memory using fMRI and multivoxel analyses. Specifically, we examined the differences across face-occupation pairings as a function of whether the pairing was viewed as a person performing the given job (unitized binding) or a person saying they knew someone who had a particular job (non-unitized binding). The results show that at encoding, the angular gyrus can discriminate between unitized and non-unitized target trials. Additionally, during encoding, the medial temporal lobe (hippocampus and perirhinal cortex), frontal parietal regions (angular gyrus and medial frontal gyrus) and visual regions (middle occipital cortex) exhibit distinct neural patterns to recollected unitized and non-unitized targets. Furthermore, the medial frontal gyrus and middle occipital cortex show greater neural similarity for recollected unitized trials than those of recollected non-unitized trials. We conclude that visually unitized pairs may enhance unitization in older adults due to greater similarity of trials within the same condition during the encoding process.

neuroscience↗

bioRxiv2022

Investigation of the neural effects of memory training to reduce false memories in older adults: Univariate and multivariate analyses

The growing population of older adults emphasizes the need to develop interventions that prevent or delay some of the cognitive decline that accompanies aging. In particular, as memory impairment is the foremost cognitive deficit affecting older adults, it is vital to develop interventions that improve memory function. This study addressed the problem of false memories in aging by training older adults to use details of past events during memory retrieval to distinguish targets from related lures. We examined the neural basis of a retrieval-based monitoring strategy by assessing changes in univariate BOLD activity and discriminability of targets and lures pre and post training. Results showed training-related decreases in false memory rates with no alterations to hit rates. Training and practice were associated with altered recruitment of a frontoparietal monitoring network as well as benefits to neural discriminability within network regions. Participants with lower baseline neural discriminability between target and lure items exhibited the largest changes in neural discriminability. Collectively, our results highlight the benefits of training for reductions of false memories in aging. They also provide an understanding of the neural mechanisms that support these reductions.

neuroscience↗

bioRxiv2022

Neural Distinctiveness and Reinstatement of Hippocampal Representations Support Unitization for Associations

The medial temporal lobe (MTL) is critical to associative memory success. Yet not all types of associations may be processed in a similar manner within MTL subregions. In particular, work suggests that intra- and inter-item associations not only exhibit differences in overall rates of recollection, but also recruit different MTL subregions. Whereas intra-item associations, akin to unitization, take advantage of associations between within-item features, inter-item associations form links across discrete items. The current work aimed to examine the neural differences between these two types of associations using multivariate neural analyses. Specifically, the current study examined differences across face-occupation as a function of whether the pairing was viewed as a person performing the given job (intra-item binding) or a person saying that they knew someone who had a particular job (inter-item binding). The results show that at encoding, successfully recollected intra- and inter-item associations are discriminable from one another in the hippocampus, parahippocampal cortex, and perirhinal cortex. Additionally, the two trial types are reinstated distinctly such that inter-item trials have higher neural reinstatement from encoding to retrieval compared to intra-item trials in the hippocampus. We conclude that intra- and inter-associative pairs may utilize similar neural regions that represent patterns of activation differentially at encoding. However, in order to reinstate information to the same degree (i.e., subsequently successfully recollected) inter-item associations may act in a compensatory manner, while it is not necessary for intra-item associations to be reinstated to the same degree. This may indicate that intra-item associations promote more efficient reinstatement.

neuroscience↗