Title: Is Activity Silent Working Memory Simply Episodic Memory?
Abstract: The evidence for the Activity Silent Working Memory (ASWM) model can be interpreted as evidence of the involvement of episodic memory (EM) in working memory (WM) tasks. EM is subject to proactive interference (PI), which has been assumed to limit its engagement in WM tasks; however, context representations actively maintained in WM can be used to mitigate PI, thereby allowing EM to be effectively used in WM tasks. The hypothesis that EM is involved in WM tasks leads to testable predictions about how the neural substrates of EM (e.g., the hippocampus) should be engaged in these tasks. This hypothesis also implies that, to predict behavioral memory performance in these tasks, we need to measure the structure of context representations maintained in WM and how these change over time (e.g., larger context shifts should lead to less PI). Working memory (WM) maintains task-relevant information in a state ready for processing. While traditional theories assume that sustained neuronal activity is responsible for WM, the Activity Silent WM (ASWM) account proposes that maintenance can also be supported by short-term synaptic weight changes. Here, we argue that the evidence for ASWM can be explained more parsimoniously by the involvement of episodic memory (EM) in WM tasks. Like ASWM, EM relies on rapid synaptic modification that is also activity silent; however, while ASWM posits transient synaptic modifications, EM traces persist over longer time periods. We discuss how, despite this difference, well-established EM mechanisms can account for the key findings attributed to ASWM, and describe predictions of this account. Working memory (WM) maintains task-relevant information in a state ready for processing. While traditional theories assume that sustained neuronal activity is responsible for WM, the Activity Silent WM (ASWM) account proposes that maintenance can also be supported by short-term synaptic weight changes. Here, we argue that the evidence for ASWM can be explained more parsimoniously by the involvement of episodic memory (EM) in WM tasks. Like ASWM, EM relies on rapid synaptic modification that is also activity silent; however, while ASWM posits transient synaptic modifications, EM traces persist over longer time periods. We discuss how, despite this difference, well-established EM mechanisms can account for the key findings attributed to ASWM, and describe predictions of this account. process that retains information in patterns of neural firing; a key signature of this process is that retained information at each time point can be decoded from neural activity. retention of a memory for a period during which any neural activity associated with the memory becomes indistinguishable from baseline levels (measured outside the retention period). an account of activity silent memory positing that memories can be retained through short-term synaptic plasticity (i.e., rapidly forming, transient associations) in addition to active maintenance in WM. neural activity that is not directly related to the sensory and semantic features of currently attended items; posited to have an important role in organizing memory retrieval. memory system that can support the formation of arbitrary novel associations (e.g., item to context) and the recall of these associations over an extended period of time, after a single study exposure; neurally instantiated as rapid long-term plasticity; thought to depend on the HPC. a context representation that carries information about the serial position of an item. situation in which previously formed memories impair present task performance; arises when many similar memories coexist. a context representation that changes smoothly (i.e., drifts) over time and thus carries information about the passage of time. a context representation that changes abruptly at trial boundaries and thus serves to distinguish memories formed in different trials. memory task designed to isolate WM processes; characterized by short delay periods and requiring flexible updating of contents maintained in memory. a flexible memory system that retains information over a period of seconds to minutes, beyond immediate sensory inputs. The prefrontal cortex is thought to be a key neural substrate of WM.
Publication Year: 2021
Publication Date: 2021-04-01
Language: en
Type: review
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 76
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot