Consolidation and Reconsolidation of Long-Term Memory

The discussion in this essay will focus on the consolidation and reconsolidation of long-term memory, it will show cognitive and biological research, and there will be a discussion on which tests were undertaken and what information was returned. The consolidation theory will be analyzed and an in-depth look at how this theory was used. This essay will discuss how memory consolidation works and how synapses transfer signals from neuron to neuron with the assistance of neurotransmitters in the brain. Memory will be analyzed and discussed and some of the structural changes, which are made, will be explored. The SMS problems will be looked at and show what issues there are within this, for example, for the treatment of episodic and semantic memory there is no equivalent way to treat the episodic memories and how they become much more semantic in time. Also, the role of the hippocampus will be explored, looking into whether the hippocampus gradually diminishes, and the ability for structured cortical networks to ensure retrieval of remote memories independently

Consolidation is described as a process that fixes information in long-term memory over a period of time, which may range from a few hours to a few days. Consolidation theory is claimed to be the preferred theory among neuroscientists; however, the majority of cognitive psychologists dismiss it. . Eysenck W. Keane T.. While the consolidation process makes it easier to recover memories when they are needed, memories are not permanent after they've been consolidated. And As a consequence, the process of reconsolidating a memory will independently boost information retained in long-term memory memories. Ref. According to, Lechner et al. When they noticed that the people who were chosen to take part in their experiment frequently presented similarities for syllable pairs to become present between training sessions, they analyzed the report of the volunteers and discovered evidence for perseveration during the recall test, it was seen that a minority of the people who were chosen to take part in their experiment frequently presented similarity for syllable pairs to become present between training sessions, they analyzed the report of the volunteers and they discovered evidence for perseveration during the recall test,' Participants were asked to check syllable comparisons in the result of the peculiar message, and in subsequent studies, they were said to have used a similar syllable incorrectly due to another incite. ‘'The effects were said to be at their height right after the training, however, they gradually faded during the training, and after one day, they were said to have vanished. present, Lechner et al.

Amnesia research has been said to prompt new scientific ideas which are said to serve as a testbed for current theories. Amnesia can be caused by damage to the diencephalon or the medial temporal lobe, both of which are said to belong to the same functional system. there has been testing that has shown that a number of amnesiac patients present damage to the hippocampal zone, which is said to disrupt consolidation processes which create a temporal gradient in retrograde amnesia, according to W. Eysenck and T. Keane. The principles of the 'Hebb synapse,' 'Hebbian cell assembly,' and 'Phase series' are said to have played a major role in the advancement of behavioral neuroscience over the last 70 years, according to Hebb's The Organization of Behaviour. Ebb also made a critical observation about how memories are created in the brain, which he disguised as improved synaptic effectiveness in a cell assembly. He proposed that the reverberation that occurs within a cell assembly, which is initially activated by some external input, could hold the memory alive for a short time.

As ideas about system-level memory consolidation evolved, the belief that short-term memory and long-term memory exist within the same circuits was rejected. Hebb's assemblies were created to physiologically capture temporal associations by strengthening the connection between neuron A and neuron B whenever activity in one leads to activity in the other. Hebb's concept, on the other hand, gave no indication about the need for an assembly of neurons to be temporally synchronous; however, such synchronicity is presumed in more recent versions by Abeles.

The traditional model of memory consolidation, visual, motor, and cognitive knowledge is initially processed by several other specialized primary and associative cortical areas defined by cortical modules. gradually decreases, allowing hierarchical cortical networks to independently retrieve distant memories. This method, according to the study, involves not only the strengthening of established cortical-cortical connections but also the formation of new connections between previously unconnected neurons through repeated activation of hippocampal-cortical networks during periods of quiet wakefulness or sleep.

The hippocampus's functional position progressively decreases as cortical memories age and become more stable, e.g., Changes in the strength of hippocampal-cortical connections are quick but short-lived, while changes in the strength of cortical-cortical connections are sluggish but long-lived, and dependently capable of maintaining and mediating the retrieval of permanent memories. McClelland et al. The following are said to be the issues with SMS:

Both the memory task being studied, and the procedure used to induce amnesias, such as lesions, electroconvulsive shock, immersion in cold water, or injection of protein synthesis inhibitors, affect the apparent magnitude of RA and therefore the duration of the consolidation period, according to; Squire and Alvarez. Consolidation in the animal literature is measured in hours, days, or weeks, while in the human neuropsychological literature, consolidation is measured in years.

There has been no empirically supported mechanism proposed to achieve this. Since the SMC treats episodic and semantic memory as interchangeable, it provides no explanation for how episodic memories evolve over time. Because the SMC considers episodic and semantic memory to be interchangeable, it doesn't explain how episodic memories evolve into semantic memories over time. While the model suggested by attempts to answer this issue, it does so while ignoring the ongoing existence of episodic memory. In addition to these and other limitations in standard theory, Nadel and Moscovith.

The Theory of Multiple Traces (MTT). While the model presented by attempts to answer this issue, it does so while ignoring the ongoing existence of episodic memory. Nadel and Moscovith developed a new paradigm called the multiple trace theory to address these and other flaws in the traditional theory. As an alternative to the traditional model, Nadel and Moscovitch proposed the competing theory, known as the Multiple Trace Theory (MTT). Unlike the SMC, MTT believed that the hippocampus is involved in the retrieval of all episodic memories, including distant ones. MTT suggested, like the SMC, that memories are encoded in hippocampal-neocortical networks, with each reactivation resulting in a different hippocampus trace is thought to be contextual, with a lot of spatial and temporal variation. Cortical-bound traces are thought to be semantic and mostly context-free, whereas hippocampal-bound traces are thought to be contextual and rich in spatial and temporal information. The hippocampus is not required for retrieval of remote semantic memories, but retrieval of remote episodic memories is, regardless of the memory's age.

without the involvement of the medial temporal lobe memory system, Every consciously observed event will be composed of a coherent hippocampal-cortical ensemble, according to the multiple trace theory. Nadel and Moscovitch posit that the repeated creation of multiple hippocampal-cortical traces will favor the fusion of information with pre-existing knowledge to form old semantic memories (memory for general knowledge of facts) whose retrieval could probably occur. According to these researchers, retrieval will often necessitate the involvement of hippocampal-cortical networks ('R - Personality Disorders - ALPF Medical Research', n.d.) However, it became apparent much later that neuropsychological research methods in that period were not as refined, and that episodic memory may not have been thoroughly tested. H. M. was unable to provide an episodic memory of his mother or father, he was unable to narrate even one incident that happened at a particular time and place, Corkin later said.

Patient E. P., a case of profound amnesia studied by Squire and colleagues, was able to show extremely specific spatial remote memories Stefanacci et al., contradicting the idea of a flat episodic RA gradient. This was said to be complicated even further by the heterogeneity of findings across studies of different amnesic patients with a partial medial temporal lobe or hippocampal damage, to which the lack of detailed neuroanatomical quantification in many cases. As a result, amnesia evidence for the RA gradient is said to be inconclusive, providing only limited and sometimes contradictory support for both major theories.

The Normative Model of Systems Consolidation, a widely influential view in the field, compares systems consolidation with multiple trace theory. The SMSC states that the original memory trace is encoded in both the hippocampus and the cortex, despite the cortex's failure to sustain the memory initially. Instead, the hippocampus is important during the early stages of encoding. The hippocampus teaches the cortex the memory trace as a function of time, replay, and retrieval so that the associative connectivity between the individual elements is retained. Squire and Alvarez, The hippocampus is no longer required for retrieval after the memory has been consolidated. The multiple trace hypothesis argues that the hippocampus plays a permanent role in memory storage and recovery as long as memories remain, which is an alternative and difficult perspective according to the writer. Moscovitch and Nadel.

This viewpoint is backed up by three key lines of clinical and scientific evidence that the traditional model of memory consolidation cannot account for. First retrograde amnesia can be ungraded (i.e., 'flat') in some cases, with both recent and distant memories being equally affected Cipolotti et al. Second, retrograde amnesia gradients have been discovered. Second, some retrograde amnesia gradients have been reported in some amnesic patients to last for decades, if not nearly the entire human life span, raising the question of the ethological meaning of such a long consolidation period. Third, the form of declarative memory to be consolidated can influence the detection of a retrograde amnesia gradient and its temporal extent (episodic, semantic, or spatial). SMC and its forecasts According to SMC, all explicit memories both episodic and semantic) are still preserved in extra hippocampal circuits in their current form. The hippocampal contribution takes the form of an 'index,' which connects the different neocortical sites that describe the various parts of an episode, or the semantic structure abstracted from similar episodes. In comparison to MTT, this position appears to make some important predictions.

Since the hippocampus isn't interested in retrieving distant memories, such retrieval should not be followed by hippocampus activation. In terms of device convergence, both episodic and semantic explicit memory are handled equally. Both are reliant on the hippocampus at first but gradually become self-sufficient. Moscovitch et al. MTT and its forecasts Memories are processed jointly in hippocampal and extra hippocampal circuits, according to MTT, and episodic and semantic memory are treated differently.

The information in episodic memory is stored in both hippocampal and extra hippocampal circuits, allowing remote epistemological recall. When it comes to systems consolidation, the two types of explicit memory, episodic and semantic, are handled differently. Moscovitch et al. MTT claims that episodic memories, at least in their most comprehensive form, are often based on hippocampal circuits. Semantic memories, on the other hand, may function independently of hippocampal circuitry in the same way as standard theory suggests.

That is, semantic knowledge is often reflected in extra hippocampal circuits, and the consolidation process acts to reinforce these circuits and incorporate suggestions. Incorporating newly acquired semantic data into existing stores

Nadel and colleagues, n.d. Reconsolidation vs. Consolidation states that cellular substrates of consolidation and reconsolidation are different. plasticity molecules or plasticity inside certain brain structures that are necessary for consolidation but not for reconsolidation According to Milekic and colleagues 2000, Suzuki et al., 2004.

Several reconsolidation experiments have shown that memories become immune to reconsolidation blockers over time, but other studies have shown the opposite. , Debiec et al., (2002); Wang et al., (2009); Robinson et al., (2010). Nadel et al., n.d. As mentioned by Alberini, Due to the importance of active memory as a boundary state, a difference in the predominance of the memory during initial learning versus following the reminder event may lead to a difference in susceptibility to interference, according to the researchers. McGaugh stated that in behavioral paradigms (especially aversive conditioning tasks), arousal is likely to be bigger during original learning than during the reminder, specifically if the reminder is the cs alone. Seeing that arousal plays a significant role in consolidation dissociations between consolidation and reconsolidation. The results on the blockade of reconsolidation following molecular treatments, hippocampal lesions, and inference, taken together, have led some to speculate that reconsolidation usually requires memory updating.