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Post-traumatic stress disorder
Published in Alison Brodrick, Emma Williamson, Listening to Women After Childbirth, 2020
Alison Brodrick, Emma Williamson
Over the past few decades, several theories and models of how PTSD develops have been proposed. As Grey (2007) explains, these models are not mutually exclusive but have differing emphases. Rooted in cognitive neuroscience, Brewin and colleagues developed the ‘dual representation theory’ of PTSD (Brewin et al, 1996; Brewin, 2003; and updated by Brewin et al, 2010), focusing on the nature of memory within PTSD. In this model, different memory systems within the brain are described to explain how normal, healthy memories are distinct to traumatic memories. Two main memory systems are proposed: contextual memory (akin to ‘narrative’ memory that is easily accessed in language) and low-level sensation-based memory that is perceived through senses. ‘Healthy’ memory relies on connection between these two memory domains, with interaction between narrative memory and sensation-based memory. In PTSD, it is thought that memory encoding involves relatively stronger sensation-based memory, weaker ‘narrative’ memory, and impaired connections between the two, resulting in a fragmented and disorganised overall recall of the event, with strong, vivid aspects of memory that can be experienced via reliving and flashbacks. A commonly seen example of this within our clinic is women describing an ongoing sense of feeling the canula in their hand, as this sensation has been encoded so strongly and not updated or elaborated by the narrative that would provide the awareness that this sensation belongs to an event in the past.
Conducting the Investigative Interview
Published in Darrell L. Ross, Gary M. Vilke, Guidelines for Investigating Officer-Involved Shootings, Arrest-Related Deaths, and Deaths in Custody, 2018
R. Edward Geiselman, James F. Wilson, Alexis Artwohl
In a rare study of high intensity stress at the time of experiencing the event that was actually induced by the event (as opposed to “artificially”), Morgan et al. (2004) found that witness memory performance 24 hours later was poorer for those who had undergone the high stress versus the low stress (prior) experience. They concluded that high stress may have contributed to a disruption of memory encoding. They also noted that other studies: have shown that the consolidation of memory may occur over a number of days after stress exposure. It is possible that memory for the low-stress condition consolidated more rapidly than for the high stress condition and that an assessment at a later time point may have reduced the observed differences in memory between the two conditions.(Morgan et al., 2004, p. 276)
Memory
Published in Allan Hobson, Psychodynamic Neurology, 2014
It has generally been assumed that memory encoding occurs in waking and that only consolidation effects, like those alluded to above, occur in sleep. This is a questionable assumption especially given the bizarreness of dreams. It is really dream bizarreness that has inspired the imaginative attempts at decoding that are called interpretation. The interpretation of dreams is age old. The most recent, and possibly the most imaginative of dream interpretive theories, is the psychoanalytic hypothesis of Sigmund Freud. I have used the disguise-censorship mechanism, which Freud invented, as a foil for my 1977 activation-synthesis theory inspired by cellular and molecular neuroscience. But until now, the best I could do to explain dream bizarreness was to emphasize randomness, an idea rightfully scorned by those who believe, as I still do, that dreams really do mean something. But what that something is, and whether that something can ever be scientifically validated, remain uncertain.
Motor behavior-induced prefrontal cortex activation and episodic memory function
Published in International Journal of Neuroscience, 2021
Paul D. Loprinzi, Lindsay Crawford, Damien Moore, Jeremiah Blough, Grace Burnett, Morgan Chism, Gina Robinson
In a multivariable linear regression evaluating the association between PFC oxygenation (IV) and memory performance (DV), and after controlling for age, gender, race-ethnicity, education, handedness (laterality quotient), and overall baseline PFC oxygenation, for every 1μM increase in overall PFC O2Hb during memory encoding, there was a 0.27 increase in the number of words (out of 8) recalled (b=0.27; 95% CI: 0.02, 0.52; p = .03). When expressed as a standardized coefficient, for every 1 SD increase in PFC O2, there was a 1.55 increase in the number of words (out of 8) recalled (β = 1.55, p = .03). This model explained a statistically significant amount of variance in memory performance (R2 = 0.22; F(7, 73)= 2.69, p = .01). Thus, the degree of PFC oxygenation during memory encoding is associated with behavioral memory performance. Overall, PFC oxygenation during memory retrieval was not, however, associated with memory performance. After controlling for age, gender, race-ethnicity, education, handedness (laterality quotient), and overall baseline PFC oxygenation, for every 1μM increase in overall PFC O2 during memory retrieval, there was a 0.20 increase in the number of words (out of 8) recalled (b=0.20; 95% CI: −0.04, 0.45; p = .09).
Current practice of cognitive rehabilitation following traumatic brain injury: An international survey
Published in Neuropsychological Rehabilitation, 2020
Clare Nowell, Marina Downing, Peter Bragge, Jennie Ponsford
Functional compensation involves developing alternate strategies and utilizing remaining abilities to complete everyday tasks, circumventing or lessening the burden of impairment (Institute of Medicine, 2011; Ponsford et al., 2012). For example, a strategy utilized for memory impairment might involve the internal process of visual imagery, to increase conscious engagement during memory encoding (Velikonja et al., 2014). External functional compensation strategies for memory might involve utilizing physical systems of compensation, such as diaries and electronic devices including mobile/smart phones (Velikonja et al., 2014; Wilson, 2009). For individuals with impairments in memory and executive functioning, techniques such as errorless learning, which involves providing prompting to avoid making errors during training, can facilitate the learning of functional compensatory strategies (Ehlhardt et al., 2008). Modifications to the environment or structured support provided by another person are also considered external compensatory strategies aiming to increase functional independence or participation (Ponsford et al., 2012; Velikonja et al., 2014).
Acute psychosocial stress during retrieval impairs pattern separation processes on an episodic memory task
Published in Stress, 2020
Jonas P. Nitschke, Lisa-Marie Giorgio, Oliwia Zaborowska, Signy Sheldon
There is clear evidence that acute psychosocial stress impacts episodic memory processing with differential effects emerging during memory encoding and retrieval (Schwabe, Joëls, Roozendaal, Wolf, & Oitzl, 2012). Studies have linked stress to benefits when encoding an episodic memory, particularly for emotional material (Ulrich-Lai & Herman, 2009). However, stress is also linked to deficits in memory retrieval, mainly by impairing the ability to recall previously learned material (Gagnon & Wagner, 2016; Schwabe, 2017; Shields, Sazma, McCullough, & Yonelinas, 2017) (however: Domes, Heinrichs, Reichwald, & Hautzinger, 2002). A characteristic of successful episodic memory retrieval is the ability to discriminate new and similar experiences from those that have been previously encountered, coined behavioral pattern separation (Yassa & Stark, 2011). Among the memory-related brain regions affected by stress are regions in the prefrontal cortex important for executive processes (Shields et al., 2016) as well as the hippocampus, which plays a critical role in memory-based processes needed to engage in behavioral pattern separation, also referred to as memory discrimination (Gagnon, Waskom, Brown, & Wagner, 2019; O’Reilly & Norman, 2002). Here, we focused on testing how the effects of stress at retrieval present as deficits in memory discrimination.