Can a person experience abuse or another traumatic event without subsequently remembering it? Can such experiences have lasting psychological or physiological consequences? And can experiences that are no longer consciously accessible be reconstructed through psychotherapy?

These questions require a distinction between the occurrence of an event, the formation of a memory, and the later retrieval of that memory. Research has established that experiences can influence learning, behavior, and physiological development without remaining accessible as conscious autobiographical memories. This is particularly relevant to infancy and to events occurring under the influence of drugs, sedation, or anesthesia.

At the same time, experimental memory research demonstrates that suggestion, imagination, and misleading information can alter autobiographical memories and sometimes produce convincing memories of events that never occurred.

This article examines infantile amnesia, implicit learning, drug-induced memory impairment, false-memory formation, and the clinical implications of attempting to reconstruct inaccessible experiences. It complements Elizabeth F. Loftus’s 1995 article: → Remembering Dangerously.

1. How Human Memory Is Formed and Retrieved

Human memory is not a continuous recording of experience. Different forms of memory depend on partly distinct neural systems, and remembering involves reconstructive processes rather than the playback of an unchanged record.

Encoding is the initial processing of information; consolidation involves stabilization of memory representations; and retrieval involves accessing previously encoded information. A failure at any of these stages can result in incomplete or absent conscious recollection.

Information that was never adequately encoded or consolidated cannot necessarily be recovered by providing stronger retrieval cues. Conversely, some temporarily inaccessible information may become available under different circumstances.

Explicit and implicit memory

Explicit memory refers to information that can be consciously recalled or recognized, including autobiographical episodes. Implicit memory refers to effects of previous experience on behavior or performance that do not require conscious recollection of the original learning episode.

Examples of implicit learning include conditioned responses and procedural skills. The hippocampus and associated cortical networks play important roles in episodic memory, while other neural systems contribute to conditioning, procedural learning, and emotional responses. Implicit memory is not an alternative recording system from which the historical details of an event can be reliably reconstructed.

2. Infantile Amnesia and Early Childhood Memory

Most adults have few, if any, reliable autobiographical memories from the first two or three years of life. The earliest memories commonly reported by adults date from approximately three to four years of age, although considerable individual variation exists.

Infantile amnesia is not an inability to learn during infancy. Babies demonstrate multiple forms of learning and memory. Durable autobiographical memory depends on interacting neurological and cognitive processes that develop throughout early childhood.

Development of the hippocampus

The hippocampus is important for encoding and organizing episodic information. During infancy and early childhood, hippocampal circuits undergo substantial development and reorganization.

Akers and colleagues (2014) experimentally investigated whether high rates of neurogenesis contribute to early forgetting. In mice, increasing hippocampal neurogenesis promoted forgetting, while reducing it during infancy diminished forgetting. These findings support a possible mechanism but do not establish that all human infant memories disappear through neurogenesis.

Other developmental influences include language, temporal organization, autobiographical self-understanding, and the ability to construct coherent narratives about personal experiences.

Are traumatic memories exempt?

There is no convincing evidence that traumatic experiences during infancy are automatically preserved as accurate autobiographical memories while ordinary experiences are forgotten.

Mark L. Howe argues that developmental limitations and ordinary forgetting provide better-supported explanations for infantile amnesia than the assumption that early memories remain intact but psychologically repressed. His review was published online in 2022 and appeared in a 2024 journal issue.

This does not mean that traumatic experiences during infancy are harmless. Experiencing an event and retaining a consciously retrievable autobiographical memory are separate questions.

3. Evidence of Memory Encoding During Infancy

Yates and colleagues (2025) used functional magnetic resonance imaging to investigate memory encoding in awake infants. They found that hippocampal activity during exposure to unfamiliar visual information predicted subsequent memory-related behavior, particularly in infants older than approximately one year.

These findings challenge the simple assumption that infants are incapable of encoding individual experiences. Some neural mechanisms supporting episodic encoding are already functioning during infancy.

What the study does not establish

The experiment investigated relatively short-term memory for presented visual information. It did not demonstrate that these representations remain accessible into adulthood, nor did it investigate traumatic experiences, abuse, or therapeutic memory recovery.

The ability to encode an experience during infancy does not necessarily imply that it will remain accessible as a conscious autobiographical memory decades later. Whether some early representations persist in inaccessible forms remains an active area of research.

4. Can Early Trauma Have Consequences Without Conscious Memory?

Research on early adversity demonstrates that experiences can influence development without being retained as conscious autobiographical memories. Repeated or severe adversity can affect stress-response systems, emotional regulation, and developing relationships with caregivers.

The Harvard Center on the Developing Child describes how excessive or prolonged activation of stress-response systems, particularly without supportive relationships, can disrupt aspects of brain and bodily development. Such effects may contribute to increased vulnerability to psychological and physical health difficulties later in life.

An infant repeatedly exposed to frightening or painful interactions may develop learned responses to particular situations or stimuli without an explicit understanding of the experience or a retrievable narrative.

These findings concern developmental processes and statistical associations. Protective relationships, subsequent experiences, and individual differences substantially influence outcomes. Anxiety, emotional dysregulation, heightened arousal, or discomfort with physical contact can arise through numerous pathways.

No particular symptom or combination of symptoms can reliably establish that someone experienced sexual abuse during infancy. The relationship between early adversity and later functioning is probabilistic, not deterministic.

5. Implicit Memory and the Concept of Body Memory

The expression body memory can refer to established phenomena such as motor learning, conditioned physiological responses, and changes in autonomic regulation. It is also sometimes used to suggest that the body preserves detailed information about traumatic experiences that cannot be consciously remembered. These claims require separate evaluation.

Previous experiences can influence physiological and behavioral responses without conscious recollection. Conditioned fear, motor learning, and some autonomic responses are established phenomena. This does not require the assumption that muscles or other peripheral tissues independently store autobiographical narratives.

There is no scientifically validated method for identifying the precise historical origin of an emotional or bodily response solely from that response. Fear, trembling, muscle tension, or intense emotion during therapy may be genuine and clinically significant, but they cannot establish whether abuse occurred, at what age, or who was responsible.

Trauma and bodily responses

Bessel van der Kolk’s The Body Keeps the Score has increased interest in the physiological consequences of trauma. Relationships between stress, neural functioning, and bodily regulation are supported by research; claims that specific traumatic events can be reconstructed from bodily sensations remain disputed.

Critics including Richard McNally have challenged some broad claims about traumatic memory. The appropriate scientific approach is to evaluate individual mechanisms rather than either accepting or rejecting everything described as body memory.

Bodily responses may reflect previous learning or adversity, but they are not reliable historical records of specific events.

6. Abuse During Drug-Induced Amnesia, Sedation, or Unconsciousness

Abuse occurring while someone is drugged, heavily sedated, or unconscious presents a different memory problem from infantile amnesia. A developed memory system may be unable to encode or consolidate information normally. Being unconscious must also be distinguished from being conscious but unable to form lasting memories.

6.1 Drug-induced anterograde amnesia

Anterograde amnesia refers to impaired formation of new memories after the onset of an amnestic condition. Benzodiazepines such as midazolam and flunitrazepam are associated with anterograde amnesia. Alcohol can substantially impair memory consolidation. Other substances, including GHB and ketamine, may cause sedation, altered consciousness, and memory impairment through differing mechanisms.

Impairment depends on dose, timing, interactions, and individual susceptibility. It is not necessarily complete: some information may be retained while other information is lost or inaccessible.

6.2 Alcohol-induced blackouts

An alcohol blackout can occur while a person remains awake, communicates, and performs complex actions, yet fails to form durable memories of some or all events.

Fragmentary blackouts leave gaps between retained memories; contextual cues may sometimes assist recall. En bloc blackouts involve more extensive failure of memory formation, and the missing information generally cannot be recovered if it was not consolidated.

A blackout is not the same as passing out, which involves loss of consciousness.

6.3 Drug-facilitated sexual assault

Drug-facilitated sexual assault is a recognized clinical and forensic problem. Substances may be administered without a person’s knowledge, or an offender may exploit intoxication from substances consumed voluntarily. Impaired consciousness, judgment, movement, or memory may increase vulnerability.

Fields and colleagues (2022) retrospectively studied 74 adults receiving mental health services after sexual assault. Participants with impaired trauma memory exhibited fewer overall post-traumatic stress symptoms and less hyperarousal than those without such impairment; re-experiencing symptoms did not differ significantly.

The study illustrates that psychological difficulties may occur even when memory of an assault is incomplete. As a retrospective clinical-record study, it could not identify the exact mechanism of memory impairment in individual cases. Memory impairment alone cannot establish that an assault occurred or identify its circumstances.

6.4 General Anesthesia and Partial Awareness

General anesthesia is intended to prevent conscious awareness and explicit memory formation. Nevertheless, a 2021 systematic review and meta-analysis examined 61 studies involving a total of 3,906 patients across 119 separate patient groups (cohorts). Evidence of implicit memory effects was found in 43 of these 119 groups (36.1%).

The 36.1% figure refers to the proportion of patient groups in which an implicit memory effect was detected, not to the percentage of individual patients who retained implicit memories. These findings suggest that limited information processing may occur under certain anesthetic conditions. However, they do not demonstrate that detailed autobiographical memories can form during unconsciousness.

Unintended awareness during anesthesia is a separate phenomenon. Complete unconsciousness, partial awareness, and drug-induced amnesia should not be considered equivalent.

6.5 Can memories from unconsciousness be recovered?

Where some episodic information was encoded and retained, later recall may be possible, subject to ordinary memory limitations. Where encoding or consolidation was prevented, there may be no durable autobiographical representation available to retrieve.

No therapeutic method has been validated as capable of reconstructing detailed, accurate memories of events that were never adequately encoded. Hypnosis, guided imagery, and repeated imagination may instead increase confusion between imagined and experienced information.

In suspected drug-facilitated assault, prompt medical assessment, contemporaneous documentation, toxicological testing, and independent evidence may be important. Testing is time-sensitive; a delayed negative result does not necessarily exclude earlier exposure.

7. Genuine Recovered Memories and False Memory Formation

Not all memories that become accessible after a period of apparent forgetting are false. Equally, not all vivid or emotionally convincing memories are accurate.

Dodier, Barzykowski, and Souchay (2023) discuss recovered traumatic memories within ordinary involuntary autobiographical remembering. An event may have been encoded in childhood but not recalled for years; a later cue may trigger recollection. A person may also reinterpret a previously remembered event as abusive later in life.

This framework does not demonstrate that detailed autobiographical memories from infancy or periods of complete pharmacological amnesia can be recovered. The circumstances of recall cannot independently establish historical accuracy.

How false autobiographical memories form

Source-monitoring errors involve misattributing the origin of information, such as confusing imagination with experience. Imagination inflation describes increased belief in an event after imagining it. Repeated suggestion and reconstruction can combine genuine details with invented or misleading elements.

Scoboria and colleagues (2017) analyzed 423 participants from eight false-memory implantation studies. Under the authors’ coding criteria, 30.4% were classified as false memories, while a further 23% showed some acceptance of suggested events.

These experimental findings do not establish the prevalence of false abuse memories among psychotherapy patients. Confidence, vividness, and emotional intensity are not reliable guarantees of historical accuracy; independent corroboration is especially important for serious allegations.

8. The Risks of Suggestive Memory-Recovery Practices

Problems arise when therapy begins with the assumption that unexplained symptoms must originate from forgotten abuse. A therapist may interpret anxiety, relationship difficulties, dreams, or bodily sensations as evidence of abuse and then organize treatment around confirming that interpretation.

Guided imagery, hypnosis, repeated questioning, dream interpretation, or age regression can encourage increasingly detailed accounts of previously unremembered events. Such accounts may feel like discoveries rather than interpretations. This does not make every memory emerging during therapy false; it means suggestive procedures can compromise reliability.

Retracted memories and therapeutic suggestion

Otgaar and colleagues (2025) reviewed literature on people who reported recovered memories of abuse and later retracted their claims. In one selected sample, 19 of 20 retractors reported that memories emerged during therapy; in another, 33 of 40 reported that therapists suggested abuse before the corresponding memories emerged.

These are selected retrospective samples, subject to recall, selection, and reporting biases. They cannot establish the prevalence of false memories in psychotherapy. Retraction alone also does not prove that every original allegation was false.

Differences between researchers and practitioners

Patihis and colleagues (2014) documented differences in beliefs about repression and memory recovery between memory researchers and some clinician groups. The study also found that belief in repression among mainstream clinicians had declined relative to earlier surveys.

The clinical concern is not that therapists should reject reports of abuse, but that they should avoid introducing unverified historical explanations as established facts.

9. Clinical Implications and Professional Guidance

The American Psychiatric Association’s position statement on therapies focused on memories of childhood physical and sexual abuse, reaffirmed in 2013, recognizes both the serious consequences of genuine abuse and the potential harm of accepting inaccurate memories as historical facts.

It recommends an empathetic, nonjudgmental, neutral approach. Therapists should not begin with a predetermined assumption that abuse either did or did not occur. The statement addresses attempts to elicit previously unremembered experiences; it should not be interpreted as dismissing independently corroborated histories or memories present before therapy.

Treatment without reconstructing the past

Psychological distress can be addressed without establishing a specific forgotten event. Treatment may focus on anxiety, sleep disturbance, emotional regulation, interpersonal problems, and distressing physiological responses while acknowledging uncertainty about historical causes.

Psychological treatment and historical investigation have different purposes and evidentiary standards. A therapeutic interpretation is not independent corroboration; uncertainty about a historical event does not invalidate a person’s present distress.

10. Summary of the Scientific Evidence

Established: Infants learn and encode information; early adversity can influence development without conscious autobiographical recall; drugs can impair memory formation while a person remains awake; some information processing can occur under certain anesthetic conditions; and suggestion can produce convincing false autobiographical memories.

Supported with important qualifications: Early adversity can affect later emotional and physiological regulation, but outcomes vary and symptoms are not diagnostic of a particular history. Some childhood memories may become accessible after a period of non-recall, but their accuracy cannot be inferred from how they emerged.

Not established: That detailed autobiographical memories of infancy are routinely preserved and recoverable in adulthood; that bodily sensations identify particular forgotten abusive events; or that hypnosis, guided imagery, or other therapeutic methods can accurately reconstruct events that were never adequately encoded.

Clinical implication: A person can have experienced abuse without remembering it, but absence of memory is neither proof of abuse nor proof that abuse did not occur. Likewise, a vivid recovered memory requires careful evaluation rather than automatic acceptance or rejection.