Cognitive psychologists and neuroscience researchers have proposed theories that explain why people forget, distort, or repress memories. From a historical perspective, Freud’s contributions on the topic of memory offered insights into the concept of forgetfulness and repression (Knafo, 2009). According to Knafo, forgetfulness stems from intentionally repressing unwanted memories to avoid emotional distress. Even though forgetfulness may be intentional, unintentional forgetting of memories is frustrating. Forgetfulness can result from retrieval-induced forgetting or contextual differentiation (Lehman & Malmberg, 2009; Storm, Bjork, & Bjork, 2008). Forgetting effects based on the theory of interference can block or distort memories due to emotional distress (Smith & Moynan, 2008). Camp, Pecher, Schmidt, and Zeelenberg (2009) argued that interference theories and inhibition theories create forgetting. Studies by Schneider and Dixon (2009) on the construction of memories indicated that disruptions in the short-term working memory interfere with maintaining memories for later retrieval. In contrast, Fabiani, Low, Wee, Sable, and Gratton (2006) argued that memory decay due to ineffective filtering of sensory information causes forgetfulness. Memory retention can be subject to memory hazards caused by proactive or retroactive interference consequences (Chechile, 2006). Even though an individual encodes information properly, some memories are subject to interference or decay during the retrieval processing (Wixted, 2005). Wixted posited that the long-term potentiation (LTP) of synaptic transmissions in the hippocampus maintains memories and contributes to memory distortion when damaged.
MacLeod and Saunders (2008) linked memory retrieval to memory distortion through an inhibitory induced mechanism. Inhibitions to avoid certain memories induce forgetting which can lead to distorted memories. Memory malfunction affect memory recall (Loftus, 2003). As Renk, Donnelly, McKinney, and Baksh (2007) pointed out, misattribution, suggestibility, and bias effects distort memories. Steffens and Mecklenbrauker (2007) argued that memories are reconstructions of schemas of past events. Memory failure distorts the information if encoding processes fail to describe the event with accuracy. False memories of repressed events result in a decline of memory accuracy over time (Brainerd, Reyna, & Ceci, 2008).
Although false memories can be harmless such as misremembering the name of a prior boyfriend, there are sources of harmful false memories. Memories vary in terms of their vividness. Perceptions, contexts, emotions, and cognition can produce familiarity. Fuzzier memories are phantom recollections of events that seem to be accurate but are susceptible to misinformation (Lampien, Meier, Arnal, & Leding, 2005). Aminoff, Schacter, and Bar (2008) contended that people embed objects in memory with other objects of similar contexts, which activates the cortical network system in the brain responsible for processing and retrieving information.
Brainerd et al. (2008) discussed the shift of false memories over time that leads to misinformation of data. Studies show that misinformation about fuzzy events can lead to suggestibility of eyewitness memories (Brainerd et al., 2008; Steffens & Mecklenbrauker, 2007). People who have experienced unpleasant encounters often repress or inhibit their experiences in order to avoid anxiety (Garssen, 2007). McNally, Clancy, Barrett, Parker, Ristuccia, and Perlman (2006) posited that abused children repress their memories in an effort to forget the traumatic event.
Repression describes the tendency to inhibit negative feelings associated with unpleasant experiences in order to eliminate any threats to a person’s self-image (Garssen, 2007). Garssen investigated the voluntary suppression of negative emotions as a coping mechanism to control and protect the inner self. Rofe (2008) focused on clarifying what people remember or forget. People have a tendency to forget trauma. Rofe argued that people do remember traumatic experiences but choose to repress such memories as an innate instinct to protect their wellbeing. From a neurobiological perspective, Anderson et al. (2004) discovered that reduced hippocampus activation suppresses unwanted memories. In addition, Buchanan (2007) posited that the neural connections in the amygdala in conjunction with the hippocampus and prefrontal cortex play a role in the retrieval of emotional experiences.
In reviewing the influences that forgetting, distortion, and repression has on memory, it is important to define these terms in order to clarify the relationship between encoding, storage, and retrieval of memories. Forgetting refers to the failure to retain previously encoded information in memory. Often cue-overload in memory storage prevents previously stored information from reaching consciousness (Wixted, 2005). Distorted memories refer to forgetting the actual details of prior experiences or events. Factors such as the encoding specificity of events, cue manipulation of events stored in memory, and retrieval cues can change the context of prior memories (Buchanan, 2007). Cognitive psychologists refer to this phenomenon as false recognition or false memories (Aminoff et al., 2008). Loftus (2003) described false memories as inaccurate recollections of events stored in long-term memory that people distort when recalled. Repression focuses on forgotten traumatic memories that people tend to suppress in their long-term memory to avoid recalling expressive negative emotions that harm their self-image and self-worth (Garssen, 2007). Piper, Lillevik, and Kritzer (2008) argued that repressing harrowing memories is an unwilling and automatic process out of conscious awareness as soon as an unpleasant event happens. For repression to occur, a person must first encode the event but be unable to recall the event (Piper et al., 2008).
Based on the information provided in the above-mentioned articles and the definitions of terms, a connection between forgetting, distortion, and repression of memories may explain the intricacies and complexities of memories in everyday life. People do forget certain memories but there may be a link between what memories a person forgets, what memories become distorted and what memories are repressed.
Knafo (2009) contended that Freud’s interest in the functioning of memory played an important role in current theories and findings. Freud distinguished forgetfulness from repression by stressing its defensive nature. Repression refers to the banishing of distressing memories from consciousness to avoid emotional distress. According to Knafo, neuroscience research supports Freud’s idea of repression. The right frontal lobe prevents painful memories from entering the left hemisphere to be processed and stored (Knafo, 2009). In essence, people want to forget the memories that cause distress. Although such memories are intentionally forgotten or repressed, Lehman and Malmberg (2009) discussed the relationship between intentional and unintentional forgetting.
According to Lehman and Malmberg (2009), free recall is the memory task that unintentionally frustrates people. The differential rehearsal hypothesis states that changing the encoding procedures through improved rehearsal techniques should enhance recall. However, the inhibition hypothesis in a retrieval-induced forgetting domain affects recall in both unintentional and intentional situations. Retrieval-induced forgetting results from a temporary incapability to recall items from memory (Lehman & Malmberg, 2009). Storm et al. (2008) hypothesized that the retrieval strength not the storage strength reduces recall. Intentionally inhibiting items from memory during retrieval creates intentional forgetting of that item while unintentional inhibition of items interferes with the recall of other items (Storm et al., 2008). Items in memory have two separate strengths. The storage strength denotes the interconnection between items in memory while the retrieval strength embodies the accessibility of items in memory at any given time and in certain contexts (Storm et al., 2008).
The contextual differentiation hypothesis states that forgetting depends on the changes in the context during encoding. Recall depends on the person’s ability to restore appropriate context cues, which reduces forgetting effects (Lehman & Malmberg, 2009). For example, to recall a misplaced item, a person needs to reconstruct a mental representation of the environment in order to recall where he or she placed the item. However, in emotional situations people can block memories of items or events during retrieval to reduce distress (Smith & Moynan, 2008).
Smith and Moynan (2008) hypothesized that there are individual distinctions in vulnerability to forgetting effects. Individuals tend to remember emotional experiences more readily than unemotional events. When given a list of emotional violent words, traumatized individuals experienced unintentional forgetting. Interference and inhibition can invoke long-term forgetting. According to Smith and Moynan, providing appropriate independent cues reverses these effects. Their studies indicated that after giving participants emotionally laden cues, it induced a reversal of forgotten memories (Smith & Moynan, 2008).
To make a distinction between interference and inhibition effects, Camp et al. (2009) hypothesized that recall depends on the relationship between items when competing for retrieval. A competing relationship between items decreases the strength between the cue and target item, which interferes with memory retrieval. Interference in the retrieval of memories decreases retrieval time and creates forgetting (Camp et al., 2009). In contrast, inhibition effects are not cue dependent. Forgetting occurs even after the presentation of cues because people can actively control items in memory and can inhibit certain memories from reaching consciousness. Despite the cues used to access items, people forget these memories (Camp et al., 2009). Similarly, Schneider and Dixon (2009) argued that disruptions in short-term working memory could impede retrieval of items in memory. Mental representations of complex tasks require individuals to eliminate any distracters during retrieval. These interruption effects symbolize the time needed to restore mental representations of the tasks into short-term memory, which reduces forgetting and increases comprehension. Thus, suggesting the visuospatial cues are important in maintaining retrieval accuracy (Schneider & Dixon, 2009).
In contrast, Fabiani et al. (2006) posited that items in memory decay over time. As people age, their working memory capacity becomes overloaded with information which effects memory. The decay theory emphasizes a reduction in attention control based on complex cognitive performances. Fabiani et al. argued that memory decay is due to a reduction in filtering irrelevant sensory information rather than decline in sensory processing due to age. The ineffective filtering combined with reduced attention control creates problems in the working memory, which in turn increases forgetting (Fabiani et al., 2006). Chechile (2006) expanded on the decay theory by examining memory hazards in retention of information. Decline in memory retention and memory span indicates improper encoding procedures caused by either proactive (before learning) or retroactive (after learning) interference (Chechile, 2006). Wixted (2005) argued that failure to encode novel information induces forgetting.
An alternative explanation for the interference theory and decay theory posited by Wixted (2005) is a lack of memory consolidation. Neuroscience research suggests that memories are susceptible to disruption during consolidation. Encoding memories involves the release of neurotransmitters in the presynaptic neuron, which causes the postsynaptic neuron to fire. This chaining of events known as the LTP mechanism responds to presynaptic neuron stimulation in the hippocampus (Wixted, 2005). Wixted posited that induced stimulation of the LPT in the hippocampus from drugs or alcohol serves as interference for forming new memories, causes forgetfulness of an earlier learned task, and impairs LTP maintenance. Alcohol and drugs can interfere with the encoding process that prevents memory consolidation by blocking memory formation and inducing forgetting. From a psychopharmacological perspective, Wixted contended that interference to the hippocampal LTP causes a failure of new memory to form (anterograde amnesia) or impairs previously formed memories (retrograde amnesia) in the consolidation process of memories. Wixted hypothesized that memory consolidation after the encoding process is subject to interference based on storage decay and retrieval overload during the retention stage, which may be the cause of forgetfulness. From a neuroscience research and psychopharmacology perspective, poor memory consolidations and retention can provoke forgetting or memory distortion (Wixted, 2005).
Distorted or False Memories
MacLeod and Saunders (2008) hypothesized that people rely on their memories to solve everyday problems. Because today’s social world is constantly changing, people need to update their memories continuously. In order to update memories, individuals have to revise their old memories with new information. However, the problem lies in determining what information is relevant. Redundant information may be necessary to solve future problems. Therefore, there is a need to retain both old and new information. The interrelationship between episodic memory of knowing where and when events happened and semantic memory of general knowledge content can create problems when accessing prior events or experiences. The retrieval-induced forgetting mechanism that inhibits unwanted memories from entering consciousness is different from the traditional interference and decay theories (MacLeod & Saunders, 2008). MacLeod and Saunders argued that retrieval inhibition underlies the misinformation paradigm. For example, when updating old memories with new memories, people tend to distort their memories when they include misleading information during the encoding process (MacLeod & Saunders, 2008). MacLeod and Saunders concluded that if people activate the inhibitory mechanism during the memory retrieval process, then the new misleading information replaces the original information, which distorts memories. Their research indicates that eyewitness reports are susceptible to post-event suggestions. Loftus (2003) also studied the effects of distorted memories when recalling prior events. According to Loftus, eyewitness informants are susceptible to suggestibility and biases of misinformation.
The misinformation effect can affect memories when questioning informants in a suggestive manner (Loftus, 2003). Misinformation about an actual event can influence a person’s perception of that event. Planting false memories of an event exposes individuals to believing something happened when in reality it did not happen. As Loftus pointed out, people’s memories are fragile and influenced by their thoughts, by what someone has told them or led them to believe. By reinventing memories, people become the person in their own imagination because their memories have malfunctioned (Loftus, 2003).
Renk et al. (2007) expanded on the memory malfunction occurrence in everyday life that affects a person’s ability to recall events. Using Schacter’s theory of memory distortion, Renk et al. contended that misattribution, suggestibility, and biases could distort memories. The misattribution effect assigns a memory to an erroneous source or to an event that did not occur. For example, individuals who have a fuzzy recollection of an event may recall facts but misattribute the facts by linking prior experiences together to form a whole picture. Even though the event is easy to recall, it may never have happened. In addition, incorporating suggestions by other people into their memories can distort the facts (Loftus, 2003; Renk et al., 2007). Suggestibility can greatly influence eyewitness testimonies (Loftus, 2003). The questioning of eyewitnesses during an investigation or trial can lead people to believe facts that did not happen by suggestions of misleading information. Misinformation of facts by the media or other biased accounts can influence people into believing something happened (Loftus, 2003). In this situation, bias refers to recall of events that support a person’s beliefs (Renk et al., 2007)..
Renk et al. (2007) discussed various types of biases that distort memories. Consistency biases promote the recall of prior beliefs to be similar to current beliefs. Hindsight biases interconnect current knowledge with past knowledge, which makes people think they knew all along what happened but simply forgot. Egocentric biases use self-enhancing mechanisms to recall prior events. Stereotypical biases manipulate memories and perceptional awareness based on diverse social cultures (Renk et al., 2007). The false memory or distorted memory phenomenon suggests that the recall of fuzzy memories is outside the control of conscious memory, which can induce forgotten, distorted or false memories (Steffens & Mecklenbrauker, 2007).
Steffens and Mecklenbrauker (2007) implied that discrepancies between forgotten memories and recovered memories are debatable. Memories of memorable prior events are more likely to be remembered that memories of traumatic experiences. People store interpretations of ambiguous situations in previously formed schemas. Steffens and Mecklenbrauker contended that the Fuzzy Trace Theory (FTT) incorporates two memory traces, which explains the false memory phenomenon. Verbatim traces refer to the actual physical stimuli while the gist traces puts meaning to the stimuli. Because verbatim traces decline quicker, false memories increase through the gist traces. Memory errors occur when improper encoding procedures do not separate episodic memories from gist information. As a result, memory distortion occurs because the encoding specificity failed to portray an episodic event with accuracy (Steffens & Mecklenbrauker, 2007).
Brainerd et al. (2008) believed that false memories are due to a decline in episodic memories. As time passes, events get fuzzier. The FTT measures the accuracy of events by administering recall tests. After giving participants misleading information about an event, they tended to distort their recollection of that event (Brainerd et al., 2008). For example, suggesting that a thief may have worn gloves and a hat elicits the illusion of a thief wearing gloves and a hat when in reality neither item may have been a fact. Brainerd et al. referred to this phenomenon as gist traces that induces perceptual inaccuracies and can lead to wrongful convictions of innocent people.
Lampien et al. (2005) argued that memories vary in content but familiarity of content produces vivid false memories. Content borrowing of similar items can activate perceptions of similarity. If items share similar perceptual contexts, people integrate their perceptions to create new memories that tend to be false. Lampien et al. referred to this experience as phantom recollections of events that borrow content from previous similar perceptions, contexts, emotions, or thoughts. As a result, familiarity produces memory inaccuracies or false memories (Lampien et al., 2005).
Aminoff et al. (2008) argued that object familiarity creates associations that predict what a person expects to see in a contextual setting within their environment. For example, seeing an object such as a desk activates visual representations of other items such as a computer or books that share the same context of items in an office. Aminoff et al. conducted several studies that investigated the cortical network activity in the brain. They hypothesized that increased activity in the cortical area elicits object familiarity of contextually related items, which in turn increases the possibility of falsely recognizing items as related. By using functional magnetic resonance imaging (fMRI) scans, Aminoff et al. were able to examine whether context affected the old to new memory recognition performance. The results indicated that the cortical regions that process contextually related items include the retrosplenial complex (RSC), the medial prefrontal cortex (MPFC), and the parahippocampal cortex (PHC) which increases in activity when participants viewed strong contextually related items. As a result, Aminoff et al. contended that people tend to store memories within a context frame, which contains prototypes of particular items. The RSC processes information is more of a gist context which interferes with the old to new responses and contributes to memory distortion as proposed by Brainerd et al. (2008) (Aminoff et al., 2008).
The current trends in the study of distorted or false memories suggest that memories are vulnerable to many mitigating factors. As Steffens and Mecklenbrauker (2007) pointed out, research on the reconstructive nature of events stored in memory is mental representations of events and experiences. People use existing schemas or prototypes as a guide for storage and retrieval of memories. To solve everyday problems, people make inferences about prior experiences and relate those experiences to the current situation (Steffens & Mecklenbrauker, 2007). However, if prior experiences caused trauma, Garssen (2007) hypothesized that people tend to repress or inhibit these memories to minimize distress.
Repression describes the desire for people to inhibit memories of unpleasant experiences to protect their positive self-image from threat. According to Garssen (2007), repressed memories can be conscious or unconscious avoidance of prior negative emotional occurrences. In some situations, people may be aware they consciously inhibit unwanted memories but empirical research shows most repressed memories are unconscious coping techniques to avoid anxiety. People who use repressive coping styles tend to distort information and make false conclusions (Garssen, 2007). McNally et al. (2006) hypothesized that repressive individuals have trouble in retrieving unpleasant situations such as child abuse. Because these individuals fail to remember specific abusive occurrences but experience related symptoms of abuse, they infer that abuse happened and simply forget the abusive situations. Their findings suggest that people who forget or suppress traumatic experiences have more difficulty in accessing those memories (McNally et al., 2006).
Piper et al. (2008) argued that suppression and repression of traumatic experiences have separate and different meanings. For example, suppression means to defer unwanted memories from consciousness (McNally et al., 2006) while repression operates unconsciously to bury memories from reaching the conscious mind (Piper et al., 2008). Piper et al. contended that scientific research on the recovered memory phenomenon lacks credibility. Repression theorists claim that traumatized people fail to remember certain details of the event (partial amnesia), simply forget details, and deliberately avoid thinking about the event. Piper et al. believe these premises are flawed. Studies show that people do recall the essential details of harrowing experiences very vividly. The trauma experienced is usually so severe that people seldom forget which refutes the everyday forgetting phenomenon. In addition, if people intentional avoid thinking of the event they are suppressing the event not repressing the event as mentioned in the above definitions. Piper et al. argued that traumatic experiences are no different from ordinary experiences. Memory recall works by assembling the neurons in the brain that represent memory to reconstruct a mental representation. The memory process of encoding, storage, and retrieval operate the same for any type of information, which a person can modify or reorganize before and after the encoding procedure. Piper et al. believed that this analysis supports the claim that science fails to support the repressed memory phenomenon.
Although repression of memories has been a debatable topic among psychologists, Rofe (2008) argued that repression is a valid concept. Research findings suggest that people are motivated to forget trauma intentionally. As Rofe pointed out, intentional forgetting of trauma does not necessarily mean using repressive coping mechanisms but unintentional forgetting is susceptible to defensive coping mechanisms. He contended that repression is a multidimensional component comprised of memory, pathogenic effects, and unconsciousness. Memories of traumatic experiences overwhelm most people and motivate forgetting. As a result, people experience a type of amnesia to deal with trauma. Pathogenic effects focus on the distortions of memories that protect wellbeing. Inhibiting emotions is beneficial to a person’s physiological and psychological wellness. Unconsciousness is a powerful cognitive system that protects a person’s wellbeing and controls the pathogenic effects of repression (Rofe, 2008). Garssen (2007) hypothesized that people do use repressive and defensive mechanisms to deal with unwanted memories. From a conceptual perspective, repression and anxiety defenses are coping strategies people use to prevent psychological harm. Garssen referred to repression as a tendency to act or cope within the environment in a certain manner to protect a person’s self-image from harm, thus, supporting the theory that repression may be unconscious techniques to reduce distress.
Although Freud suggested repression included a voluntary suppression of unwanted memories from conscious awareness, Anderson et al. (2004) proposed that neural systems within the brain control repression. From a neurobiological perspective, the hippocampus activates successful memory recollection of subjective experiences or events. In order to suppress these memories, the lateral prefrontal cortex must disengage the hippocampal activation (Anderson et al., 2004). During fMRI scans, Anderson et al. had participants deliberately suppress memories. The results indicated that the control mechanisms in the prefrontal cortex reduced the hippocampal activation, which in turn inhibited memory recall. Momentary interruptions of intrusive memory recall triggered the executive control to override retrieval of unwanted memories. Anderson et al. posited the theory that a neurobiological representation of memory helps people to control their memories in order to adjust their cognitive assessments of traumatic events.
Buchanan (2007) argued that cognitive neuroscience research suggests that the amygdala enhances emotional memories. The retrieval of mood-congruent autobiographical memories increases the neural activity in the amygdala as well as the hippocampus and the prefrontal cortex. The interconnection of the functional activity in these neural structures during the retrieval process triggers the recollection of emotional memories. According to Buchanan, the amygdala does not store unwanted memories but rater stimulates other neural networks to retrieve these memories to be experienced again. In essence, the interconnected activities of various neural networks elicit an affective state similar to the original experience. Thus, emotions do play an integral part in altering memory recall during the retrieval stage. From a neurobiological perspective, the neural networks associated with emotion affect how a person remembers an unpleasant event.
The current studies presented in this article on memory indicate that there may be a link between forgetting, distortion, and repression of memories. Freud’s discoveries revealed the persistent consequence and complexities of memories (Anderson et al., 2004; Knafo, 2009). Research into theories that explain nature of memories and their role in everyday life have contributed to finding better ways to understanding the relationship between different aspects of memory. Forgotten memories caused by retrieval-induced mechanisms limits memory recall (Lehman & Malmberg, 2009: Storm et al., 2008). The interference, inhibition, and decay theories explain blocked memories, which induce forgetting (Camp et al., 2009; Chechile, 2006; Fabiani et al., 2006; Schneider & Dixon, 2009). If prior memories fail to enter consciousness, misinformation of facts may result in memory distortion. Distorted memories or false memories result from the forgotten memories of prior experiences, which people change to fit present situations. The misinformation effect creates memory malfunctions and distorts memories (Loftus, 2003; MacLeod & Saunders, 2008; Renk et al., 2007). Inhibiting memories from entering consciousness creates repression Wixted, 2005). Repressed memories may be memories intentionally forgotten or distorted to relieve anxiety (Garssen, 2007; McNally et al., 2006; Rofe, 2008; Smith & Moynan, 2008); Storm et al., 2008).
From a neurobiological perspective, the amygdala, hippocampus, and prefrontal cortex are the main parts of the brain that play an important role in how memories are encoded, stored, and retrieved (Aminoff et al., 2008; Anderson et al., 2004; Buchanan, 2007; Knafo, 2009; Wixted, 2005). The connection between neural network functions as posited by Wixted, explains how people forget memories that have not be consolidated properly during the encoding procedure which interferes with the retention, storage, and retrieval of previously learned tasks. Aminoff et al. implied that items stored in memory are subject to increased activity in the cortical regions, which can distort memories. Both Anderson et al. and Buchanan posited that neural activity control the retrieval of information. Highly emotional events may be more susceptible to an increase in neural activity, which may modify the retrieval process of cognitive assessments.
The evidence presented in this paper provides a possible explanation for the link between forgotten, distorted, and repressed memories. Future studies on the psychological and neurobiological factors that cause memory failures may give cognitive psychologists a better understanding of the relationship and implications that different aspects of memory has on problem solving and psychological wellbeing in everyday life. Memories affect actions and changing actions creates social change.