Understanding How Traumatic Experiences Affect Memory and Brain Function

Trauma is a pervasive response that a person experiences when exposed to a terrifying situation such as emotional abuse, witnessing violence, accident, or natural disaster. However, not everyone who encounters a terrifying incident will develop trauma. A traumatized person will exhibit specific emotional symptoms both after the horrifying event and in the long term. These symptoms include but are unlimited to shock, irritability, helplessness, and difficulty processing the experience. In consequence, traumatic experiences have had an extreme impact on memory and brain function. Accordingly, comprehending the relationship between traumatic events and brain function is critical to establishing interventions for countering trauma-related disorders.

Trauma and Memory

Intrusive Memories

Individuals are likely to experience repeated sensory-perceptual impressions after a traumatic event. The experiences intrude involuntarily into consciousness, causing intrusive memories. Intrusive memories are imagery-based impressions, sounds, or bodily sensations accompanied by negative emotions (Iyadurai et al., 2019, p. 68). For example, after an accident like having a head-on car collision, the victim can recount their intrusive visuals such as hearing a “bang” of the airbags or seeing smoke, dust, or debris. Such an example shows that sensory-perceptual details, including but not limited to physical sensations, lights, and sounds, are usually encoded in the memory (Iyadurai et al., 2019, p. 68). Besides, an individual’s emotional responses and sensory awareness become heightened after experiencing a traumatic incident. The encoded images involuntarily appear in the victim’s mind, exerting negative emotions such as anxiety, fear, or distress.

Memory Loss

Traumatic events have been linked to memory loss. Bisby et al. (2020), mention that posttraumatic stress disorder (PTSD) can significantly disrupt the memory. The sensory trauma images that involuntarily enter the consciousness cause fragmented and incoherent memories. Besides, the PTSD dual-representation principle reveals that traumatic events result in high levels of emotional arousal (Bisby et al., 2020, p.267). The arousal strengthens the lower-level imagery within the Amygdala and weakens the sub-served episodic memories within the hippocampus. Memory imbalance within these brain structures hastens invasive imagery, disrupting the coherence of voluntary recall. The imbalance results in lower memory coherence, characterized by less detailed and disjointed recollections. Moreover, the emotional and psychological stress brought about by traumatic events can interfere with the brain’s ability to consolidate and encode memories. Bisby et al. (2020) explain that the struggle to recall past information results from dissociation or particular responses that emerge during extreme stress. The dissociation interferes with memory preferentially, impacting allocentric encoding and causing memory disorganization. The disorganization makes it more challenging for individuals to retrieve memories coherently and vividly.  

Neurochemical Changes

Traumatic events can result in neurochemical modifications. There is a connection between traumatic events and the alteration of the various levels of neurotransmitters (Raise-Abdullahi et al., 2023, p. 8). Neurotransmitters, such as cortisol, serotonin, norepinephrine, thyroid, and dopamine, are chemicals that relay signals to the nerve endings and serve as stress mediators. A study by Raise-Abdullahi et al. (2023) on traumatic experiences and thyroid function indicated that there exists a connection between alterations in thyroid hormone levels and psychiatric diseases. After a traumatic incidence, a victim’s hypothalamic–pituitary–adrenal (HPA) axis releases corticotropin-releasing hormone (CRH), prompting adrenocorticotropic hormone (ACTH) to secrete cortisol (Raise-Abdullahi et al., 2023 p3). Cortisol is a stress-responsive hormone that helps in the production of substances that repair tissues by enhancing the brain’s use of glucose (Raise-Abdullahi et al., 2023 p3). However, enhanced amounts of cortisol can damage neurons in the hippocampus, further compromising memory and cognitive function.

Trauma and Brain Function

Alterations in the Hippocampus

The hippocampus is a complex brain structure responsible for learning and retrieving memories. Traumatic events have been associated with the alterations and damage of this structure (Postel et al., 2021, p. 2). The hippocampal subfield changes among those with PTSD have indicated that individuals respond differently to trauma. According to Postel et al. (2021), trauma can cause a reduction in the volume of the hippocampus. Extended activation of the HPA axis and hypersensitivity of glucocorticoid receptors have resulted in dissimilar impairment in the hippocampus (Postel et al., 2021, p. 2). The damages have been linked to the shrinkage of the hippocampus, thus impairing memory function making it vulnerable to mental health conditions (Postel et al., 2021, p. 2). Also, trauma can cause impaired neurogenesis, disrupting the formation of neurons within the hippocampus. The disruption can interfere with the brain’s ability to recover from trauma-associated impairment. Research also reports that trauma can compromise the functions of the hippocampus (Postel et al., (2021, p. 4). PTSD can alter neural activity patterns, impairing significant brain functions such as memory and emotional regulation.

Functional Amygdala Changes

The Amygdala, though a small part of the brain, is crucial in processing emotions within the brain, particularly fear and threats. Upon the occurrence of a traumatic event, the Amygdala becomes hyperactive, making the victim more sensitive to perceived threats. Alexandra et al. (2021) explain that hyperactivity or damage in the Amygdala causes impaired conditioned responses, as observed in individuals with PTSD. Moreover, the prelimbic cortex (PL) and infralimbic cortex (IL) found in the amygdaloid complex play a vital role in fear conditioning and extinction (Alexandra et al., 2021, p. 248). Nonetheless, traumatic experiences can enhance fear conditioning and impair fear extinction abilities, causing persistent fear memories. Therefore, PTSD individuals can find it challenging to accept that they are no longer exposed to threats and thus experience distressing and intrusive memories. In addition, the increased Amygdala reactivity may result in emotional dysregulation (Alexandra et al., 2021, p. 247). The dysregulation results from an emotional response to stress, making it challenging for PTSD individuals to manage negative emotions.

Impact on Prefrontal Cortex (PFC)

The prefrontal cortex is a part of the brain responsible for executing functions such as impulse control, decision-making, emotion regulation, and avoidance. Trauma can cause both structural and functional changes to the PFC. Research indicates that PTSD and stress exposure are associated with decreased volumes in the PFC and structural connectivity between the cortex and other subcortical regions of the brain (Alexandra et al., 2021, p. 253). The structural and connectivity alteration can affect the way PFCs execute functions and regulate emotions, leading to heightened anxiety responses. In addition, the PFC is known to be a threat appraisal and response modulation structure. In such a case, upon the occurrence of trauma, PFC’s ability to process threat is compromised (Alexandra et al., 2021, p. 248). The challenge makes individuals with PTSD inaccurately assess and regulate their response to perceived dangers, making them vulnerable to hypervigilance and hyperarousal. Moreover, trauma can interfere with the cognitive functions of the PFC, such as decision-making and attention, causing concentration challenges.

Interventions toward Managing Trauma

Bryant (2021) suggests several approaches for managing trauma in their article. The article highlights that fear control models are adequate for adapting to trauma. The model proposes that people with PTSD are hyperresponsive to trauma reminders (Bryant, 2021, p.1). Therefore, successful adaptation requires extinction training, which entails repeatedly presenting the conditioned stimulus without the aversive outcome. Stress hormones are also essential for adapting to trauma. Humans react to stress through biological stress reactions, including a slower-acting hypothalamic-pituitary-adrenal (HPA) axis response and a fast-acting autonomic nervous system response (Bryant, 2021, p. 2). Thus, utilizing stress-modulating hormones like noradrenergic and glucocorticoid is critical for enhancing the recall of emotional memories. The article also highlights that cognitive appraisal and coping strategies, including positive reappraisal, problem-focused, and emotionally focused coping strategies, are necessary for managing trauma (Bryant, 2021, pp. 3-4). Furthermore, early interventions such as offering Psychological First Aid, Trauma-Focused Cognitive Behavioral Therapy, Pharmacological Interventions, and prevention programs are imperative for controlling trauma-related responses.

In summary, traumatic experiences significantly disrupt memory and brain function, necessitating targeted interventions for disorders. Trauma causes intrusive memories that involuntarily appear in the mind, exerting negative emotions. The events result in high levels of emotional arousal, impairing the coherence of voluntary recall and causing memory loss. Besides, PTSD causes alterations in the various levels of neurotransmitters, and this can result in psychiatric diseases. Moreover, traumatic events result in functional changes within the brain structure, including the hippocampus, Amygdala, and prefrontal cortex. The functional modifications cause memory disturbances, emotional dysregulation, attention disruption, and decision-making challenges. Even so, fear conditioning models, stress modulation hormones, and other early interventions are imperative to adapt to and manage trauma.