Scene construction and autobiographical memory retrieval in autism spectrum disorder.

Individuals with autism spectrum disorder (ASD) frequently exhibit difficulties in retrieving autobiographical memories (AMs) of specific events from their life. Such memory deficits are frequently attributed to underlying disruptions in self-referential or social cognition processes. This makes intuitive sense as these are hallmarks of ASD. However, an emerging literature suggests that parallel deficits also exist in ASD individuals' ability to reconstruct the rich spatial contexts in which events occur. This is a capacity known as scene construction, and in typically developing individuals is considered a core process in retrieving AMs. In this review, we discuss evidence of difficulties with scene construction in ASD, drawing upon experiments that involve AM retrieval, other forms of mental time travel, and spatial navigation. We also highlight aspects of extant data that cannot be accounted for using purely social explanations of memory deficits in ASD. We conclude by identifying key questions raised by our framework and suggest how they might be addressed in future research.

A Comparison of Single- and Multi-Echo Processing of Functional MRI Data During Overt Autobiographical Recall.

Recent years have seen an increase in the use of multi-echo fMRI designs by cognitive neuroscientists. Acquiring multiple echoes allows one to increase contrast-to-noise; reduce signal dropout and thermal noise; and identify nuisance signal components in BOLD data. At the same time, multi-echo acquisitions increase data processing complexity and may incur a cost to the temporal and spatial resolution of the acquired data. Here, we re-examine a multi-echo dataset previously analyzed using multi-echo independent components analysis (ME-ICA) and focused on hippocampal activity during the overtly spoken recall of recent and remote autobiographical memories. The goal of the present series of analyses was to determine if ME-ICA's theoretical denoising benefits might lead to a practical difference in the overall conclusions reached. Compared to single-echo (SE) data, ME-ICA led to qualitatively different findings regarding hippocampal contributions to autobiographical recall: whereas the SE analysis largely failed to reveal hippocampal activity relative to an active baseline, ME-ICA results supported predictions of the Standard Model of Consolidation and a time limited hippocampal involvement. These data provide a practical example of the benefits multi-echo denoising in a naturalistic memory paradigm and demonstrate how they can be used to address long-standing theoretical questions.