More specifically, explicit memory involves conscious accessing of memories and remembering and involves brain structures, such as, the medial temporal lobe, parts of the hippocampus, and the orbitofrontal cortex (Kalat, 2004, cited in Vance and Wahlin, 2008). Siegel claims that during memory recall, ‘explicit memory is coupled with an internal sensation of remembering. The encoding of explicit memory requires focal, conscious attention. Without focal attention, or with the excessive release of the stress hormone cortisol, items are not encoded explicitly but are encoded implicitly’ (Siegel, 2012). There are several types of explicit memory, such as, semantic-factual memory, which is encoded in the left hippocampus and the left prefrontal cortex, is linked mostly to language and involves the memory of the meaning that we assign to an image, for instance. Another kind of explicit memory is episodic memory, which connects pieces of semantic memory. For example, semantic memory tells me what a truck or a Labrador puppy looks like, but episodic memory tells me about the particular Labrador puppy my son got for his birthday in 2000 or the truck that passes outside my window everyday! Autobiographical memory is a type of episodic memory, which encodes in the right hippocampus and the right orbitofrontal cortex and ‘presents the unique sense of one’s self in the past, present and future’ and (Vance and Wahlin, 2008). According to Siegel (2012) autobiographical memory is the memory of oneself at some point or points in time. Autobiographical memory includes memories of events, like our first day at school, our first bicycle or memories of drawing over time and facts (date births, names, dates of historical events, etc) and autobiographical memory is less about truth and more about one’s expectations of what various memories should be like (Tulving, 2002, cited in Vance and Wahlin, 2008). Our older schemas and our positive or negative expectations impact our autobiographical memory mechanisms because all spatial, temporal and perceptual information is first interpreted by semantic memory where our beliefs about things and experiences are kept waiting for encoding. Our general beliefs and expectations determine what is retrieved and our implicit theories about the self and others, as well as, our wishes and desires become automatically activated during our experiences. In relation to this, Vance and Wahlin write that art-making can allow us to adjust and change past views and beliefs about our abilities to express ourselves. In making art products, people activate many procedural and autobiographical choices while forming a visual narrative, and also, ‘vivid original memories and highly relived memories have strong visual images associated with them’ (Rubin, Schrauf, and Greenberg 2003, cited in Vance and Wahlin, 2008). The memory of events, especially emotionally charged events often differs from what actually happened and we continually rework modified memories (LeDoux 2002; Siegel 1999, cited in Vance and Wahlin, 2008). So our artworks and creations can be a continuous reconstruction of our memories, both explicit and implicit ones.

On the other hand, implicit memory, involves parts of the brain that do not require conscious, focal attention during encoding or retrieval. Implicit memory in its nonintegrated form lacks a sense that something is being recalled from the past. Perceptions, emotions, bodily sensations, and behavioral response patterns are examples of implicit layers of processing. Implicit mental processes are mental activities, such as moods, intentions, stances, and modes that shape our perceptions, feelings, thinking, and memory – without a sense of these influences having origins within the mind, and they are on a continuum with explicit mental processes. So remembering or ‘the subjective mental experience of recollection can involve explicit ways of remembering the past with a sense of awareness of something coming from memory, or it can be implicit and it can influence feelings, thoughts and behaviors without this sense (Daniel Siegel, 2012). This process is very clearly explained in the excerpt below ‘much of our earliest years of life is encoded into implicit memory, but then its retrieval into our emotional responses, our perceptual biases, our behavioral reactions (called procedural memory), and even our sense of the body can emerge in our experience without our knowing that it is from the past. The retrieval of implicit memory is in consciousness, but we are not aware that what is arising in awareness is something derived from a past event……. and knowing this distinction can be profoundly helpful at gaining insight into one’s mental life and patterns of reactivity’ (Siegel, 2012). So summarily, implicit memory does not require conscious processing for encoding or retrieval and it refers to somatic, perceptual experiences, which include memories of how things looked and smelled, and also how we felt at the time. ‘It directs actions, reactions, and body responses with little or no conscious effort, involving multiple brain structures. The amygdala, hippocampus and medial prefrontal cortex support fear conditioning and emotional memory, the basal ganglia and motor cortex support behavioral memory, the parietal and occipital cortices facilitate perceptual memory, and the parietal cortex stores bodily memories (Carlson 2001, cited in Vance and Wahlin, 2008). Mental models, or the generalizations of past experiences, are also part of implicit memory. Siegel (2012) writes ‘mental models are akin to schema and are sometimes called invariant representations in that they have a persistent stability as they generalize experiences into a summation or model of a series of events. Mental models (schemas or generalizations of repeated experiences) and priming (getting ready to respond) are basic components of implicit memory, created by repeated past experience. Siegel (2012) writes that mental models reinforce themselves by biasing ongoing perception to conform to expectations set by prior learning and in this way can lead to a tendency to repeatedly encode similar representations with little variation This is a top-down process in which prior learning shapes ongoing perception and behavior. Vance and Wahlin also discuss how our implicit memories form mental models responsible for themes underlying the stories we tell, ignoring what contradicts them in the present (this is termed belief perseverance), and this explains why we so often hold onto to negative self beliefs or why racial prejudice tends to endure, despite evidence to the contrary (2008).

Another form of implicit memory is procedural memory, a form of implicit memory for motor behaviors. After reading Vance and Wahlin’s chapter I learnt that my procedural memory is utilized when I engage in collage processes, in particular when cutting and pasting because these activities are automatic and non-declarative. However, ‘titling the collage requires conscious efforts’ (Vance and Wahlin, 2008). Implicit memory also ‘primes us for survival from threats of all kinds’ (Cozolino 2002; LeDoux 2002; Siegel 1999, cited in Vance and Wahlin, 2008). For instance, if an infant is exposed to a loud noise, that sound is unconsciously, automatically linked to a sense of fear and startle response. Whenever the infant hears a loud noise in the future, she/he will automatically be afraid, because the brain works to anticipate, constantly shaping information about the future or present based upon past perceptions and models. So because of the way the brain works due to evolutionary demands, benign stimuli like sounds and smells, images and objects often produce inappropriate responses from trauma survivors. Similarly, childhood attachment experiences (positive and negative) with primary caregivers become implicit memories and personality traits. ‘This juggling happens automatically— outside of recall— and informs who we are and who we will become (Siegel 2001, cited in Vance and Wahlin, 2008). So it is apparent that victims of childhood abuse and / or neglect are likely to be vulnerable in all future relationships, re-enacting their earlier attachment experiences. Therefore, working with implicit memories is of great importance during therapy or while processing trauma. Becoming aware of our responses (emotions, bodily experiences and thoughts and beliefs) to stimuli can help us access implicit memories that might be triggering our responses in the present and they can help us ‘diffuse’ triggers and cues. Through this understanding and remembering we can heal, liberate ourselves, decrease fears and increase healthy decision making. Although many people may believe that decisions are always the result of rational, conscious processing, our unconscious processing and our implicit memories definitely impact our narratives, thoughts, ideas, feelings, behaviors, as well as, our decisions and choices. Jeanne McElvaney (2011) describes how implicit processes and dissociated memories shape our decisions and choices in her novel Spirit Unbroken: Abby’s Story: ‘that experience, at four years old, was locked safely away in the far, deep reaches of her awareness. While her life could not assure her safety, her mind tenderly stepped forward to shield her from knowledge that would paralyze her opportunities to laugh, play, learn, love, and grow in circumstances out of her control. Her mind could protect her from the memory, but it could not block the deep, profound inner knowing that guided her choices’. And elsewhere, McElvaney writes ‘She didn’t know that these moments, when she dug in her heels and made choices that hurt only herself, she was responding to information carefully concealed in the secret room of her mind. Neither Abby nor those around her could recognize she was passionately acting on her own behalf from experiences she couldn’t name. Her behaviour only appeared discordant because it was out of context’. These fragmented, encapsulated memories stored beyond our capacity to recall (them) and memory gaps contribute to unwise or unsafe decisions and often do not allow us to avoid pitfalls. Moreover, dissociated trauma memories are encoded differently than ordinary memories because extreme emotions interfere in normal memory function and they are stored in the area of the brain that mostly processes emotions and sensations but not language and speech. Often the feelings and bodily sensations associated with these memories are present, but the memories themselves cannot be recalled at will. Furthermore, traumatic memories are stored as isolated fragments and survivors of trauma live with memories they are not able to readily recall or with isolated and seemingly disconnected fragments of past experiences, which affect their choices, reactions, behaviours and view of the self and the world from behind the scenes. As discussed (more extensively in other texts on this website) dissociation is a biological response that separates awareness from consciousness; it is a natural, protective ability to avoid conscious awareness of experiences we cannot bear or handle and it happens automatically. It is a process or mechanism that disturbs the normally connected functions of identity, memory, thoughts, feelings, and experiences and during this process the information is separated from our normal autobiographical memory creating gaps in our memory and sense of continuity. Siegel describes dissociation as the process by which usually associated processes are dis-associated or compartmentalized from one another and claims that ‘clinical dissociation can result in blocked access to memory and emotions, bodily numbness, or impairments to the continuity of consciousness across states of mind’ (this was first described by Jean Charcot in the 19th century)/ (Siegel, 2012).

Other types of memory are working memory, short-term memory and long-term memory, which are regulated by separate brain subsystems and sometimes these memory, systems utilize the same brain structures, and at others, different brain structures. Working memory is our capacity to temporarily retain information that is useful in completing a task. Functional magnetic resonance imaging (f MRI) shows hippocampal involvement in long-term memory formation a few years after memories are stored in the frontal lobes. However, it seems that the entorhinal cortex, a subcortical area just below the orbital frontal cortex and adjacent to the midbrain structures, sustains memory consolidation processes for up to 20 years (Haist, Gore, and Mao 2001, cited in Vance and Wahlin, 2008). The strength of one’s working memory correlates with one’s capacity to learn and to manipulate new information (Gathercole and Alloway 2006, cited in Vance and Wahlin, 2008). Scientific studies have suggested that working memory is a function of three different functional components: one retains auditory, linguistic material; one holds onto visual and spatial representations; one uses information, stored in long-term memory, about how to integrate information into the logic and decision-making process of working memory. In order for a working memory to become long-term memory rehearsal is required (for instance repeating information or a word so that we can learn it). Long-term memory is the result of repetitive stimulation of neural connections in the brain over months or even years until the memory is consolidated. Every time a memory is activated, neural connections constructing the memory are stimulated and the neural network is strengthened. Consolidation of memory, the repetition of neural networks, situates long-term memory permanently in the prefrontal cortex (Vance and Wahlin, 2008). However, anxiety and high levels of stress impact our working memory and learning capacity negatively. High levels of stress significantly inhibit working memory and are associated with continuous cortisol release that can diminish hippocampal volume (Elzinga and Roelofs 2005, cited in Vance and Wahlin, 2008). Studies have found that children that have been abused and maltreated have smaller hippocampal volume and that the hippocampus’s role in mediating explicit processing can be impaired during and following overwhelming and / or traumatic experiences. Recent studies have shown that victims of childhood abuse and combat veterans alike actually experience physical changes to the hippocampus, a part of the brain involved in learning and memory, as well as how they cope with anxiety and stress. The hippocampus also works closely with the medial prefrontal cortex, an area of the brain that regulates our emotional response to fear and stress. PTSD sufferers often have impairments in one or both of these brain regions and studies of children have found that these impairments can lead to problems with learning and academic achievements (Bremner, 1998). Furthermore, damage to the hippocampus, which processes memory, may explain why victims of childhood abuse often seem to have incomplete or delayed recall of their abusive experiences (Bremner, 1996). When our body is attacked or overwhelmed our attention is divided, which results in one part of the mind focusing on a non-traumatic aspect of the environment, while an attack is underway on the body, for example, the mind will encode implicit memory but block the encoding of explicit memory for the overall event’ (Siegel, 2012). Siegel continues ‘divided attention achieves such an outcome because the hippocampus requires focal or conscious attention to create explicit encoding but implicit memory is encoded even without focal attention!’ This situation of blocked hippocampal processing of explicit memory may also be created with the effects of cortisol. As mentioned above, excessive levels of this stress hormone impede hippocampal functioning, and when this is combined with the chemical impact of adrenaline/ norepinephrine that increases the implicit encoding of fear by way of the amygdala, we see that trauma can lead to the profile of blocked explicit processing and enhanced implicit processing (Siegel, 2012). Additionally, when our amygdala is overloaded it obstructs our normal ability to focus on one thing at a time, and ignore irrelevant stimuli. ‘A damaged amygdala allows implicitly processed, unconscious emotional stimuli to slip into working memory and into consciousness in overwhelming ways’ (LeDoux 2002; Sapolsky 2004, cited in Vance and Wahlin, 2008), impacting learning among other things. Flashbacks, which can manifest as intrusive bodily sensations, extreme emotions, and images of traumatic events are the result of this blocked explicit and enhanced implicit processing and are often accompanied with terror and experienced as happening in the here and now. ‘These elements enter awareness with implicit retrieval, but their origins as memories are not present in awareness’ (Siegel, 2012). Bremner also suggests that among other typical symptoms of PTSD in children victims, including fragmentation of memory, intrusive memories, (the unconscious separation of some mental processes from the others, e.g., a mismatch between facial expression and thought or mood), and difficult emotions, flashbacks and dissociation may also be related to impairment of the hippocampus (Bremner, 1999). The hippocampus is a seahorse -shaped structure, which is located in the central part of the brain and is part of the medial temporal lobe limbic area, develops in the second year of life and allows the development of the more common form of memory called explicit memory. The hippocampus ‘plays a central role in flexible forms of memory, in the recall of facts and autobiographical details. It gives the brain a sense of the self in space and in time, regulates the order of perceptual categorizations, and links mental representations to emotional appraisal centers’ (Siegel, 2012). Siegel writes ‘we use the hippocampus to encode and store the two facets of explicit memory: factual information and autobiographical memory’, as mentioned above, and ‘as we grow beyond our second year of life, we continue to encode implicit memory but it is woven together in some cases by the hippocampus, which selectively integrates these implicit forms into their more flexibly accessed explicit facets. And then, as we continue to grow, a narrative form of memory emerges and builds on both implicit and explicit memory to weave together the narrated stories of our lives. Implicit mental models, the schemata that we don’t even know are coming from the past, can directly shape the themes of our life stories’ (Siegel, 2012).

Finally, returning to the topic of art making and healing, discoveries in neuroscience, about how the brain stores traumatic memories, have led to an increased interest in the use of art as a therapeutic process. For instance, Malchiodi  (art therapist) claims that ‘neurological researchers are speculating that a possible cause for PTSD may be the exclusion of traumatic memories from explicit memory storage and since art therapy is a visual and sensory modality, it can help access traumatic memories stored in the implicit memory, which unlike conscious narrative memory is a sensory, body-based form of memory’.  Specifically, in the treatment of PTSD art may facilitate the brain in processing traumatic events by helping people bridge sensory memories and narrative. Art making seems to provide a bridge between implicit and explicit forms of memory and ‘art making may increase verbal communication and recall of details’ (Gross and Haynes, 1998, cited in Malchiodi, 2007).  Creating art also allows buried material, knowledge and memories to surface in a less threatening way, thus reducing resistance, facilitating healing and growth and increasing insight. In addition, neurobiology research has increased understanding in relation to the development and interaction of neural systems involved in attention and AD/ HD, which opens doors to finding ways to support the development of attentional skills. Christian (2008) writes that ‘art therapists can provide an environment that supports the development of executive attentional skills that in turn lead to flexible, adaptive, coherent, energized, and stable functioning’. Safran (2002, cited in Christian (2008) has also noted that artwork by clients with AD/ HD can become a visual record that can be looked at again, allowing for further learning and this record of their artwork supports strengthening of memory, both working and long-term memory’, which is beneficial for people with attention deficits because attention largely helps to integrate implicit memories into a coherent personal narrative over time (Siegel 2006).

In any case, ‘knowing how memory works is empowering for all of us’ (Siegel, 2012) and this knowledge concerning memory and all the new findings from neuroscience now point to a more holistic and embodied and relational approach to dealing with trauma. Siegel (2012) writes ‘we should be working through the body and within relationships to make efforts to heal the mind. The regulatory aspect of mind is located in at least two places: our bodies and our relationships. Healing the mind involves going where the mind is’.

Tonya Kyriazis-Alexandri, September, 2014

References

Bremner, D. (faculty member of the Departments of Diagnostic Radiology and Psychiatry, Yale University School of Medicine, Yale Psychiatric Institute, and National Center for PTSD-VA Connecticut Healthcare System) The Invisible Epidemic: Post-Traumatic Stress Disorder, Memory and the Brain http://www.thedoctorwillseeyounow.com/content/stress/art1964.html

Christian, Darryl (2008), Art Therapy and Clinical Neuroscience, edited by Noah Hass-Cohen, Jessica Kingsley Publishers, Kindle Edition

Malchiodi, C. (2007) The Art Therapy Sourcebook, McGraw- Hill, New York

Malchiodi, C. (2007) Expressive Therapies, The Guilford Press, New-York London, the USA

McElvaney, J. (2011), Spirit Unbroken: Abby’s Story Authorhouse, Kindle Edition.

Siegel, D. (2012), Pocket Guide to Interpersonal Neurobiology: An Integrative Handbook of the Mind (Norton Series on Interpersonal Neurobiology) (p. 492). W. W. Norton & Company, Kindle Edition

Vance, R. and Wahlin, K. (2008), Art Therapy and Clinical Neuroscience, edited by Noah Hass-Cohen, Jessica Kingsley Publishers, Kindle Edition