Brain Differences from Childhood Trauma - PDF

FROM NORMAN DOIDGE: THE BRAIN THAT CHANGES ITSELF Merzenich believes an environmental factor in the critical period can affect neural circuits in autistic children or can even lead to epilepsy (helping prove the association between the two). - Does this mean that interventions can prevent epilepsy o...

FROM NORMAN DOIDGE: THE BRAIN THAT CHANGES ITSELF Merzenich believes an environmental factor in the critical period can affect neural circuits in autistic children or can even lead to epilepsy (helping prove the association between the two). - Does this mean that interventions can prevent epilepsy or autism from forming? - BDNF (brain derived neurotrophic factor) - When we do something that causes neurons to fire together, its released - Key point: BDNF closes the CP after making all connections - Merzenich believes some situations over excite neurons in children that predispose them to autism, leading to early BDNF release - All connections are sealed early so child has undifferentiated brain maps - causing brain disorders - Explains hypersensitivity as one frequency heard can cause the whole auditory cortex to fire - Explains high rates of epilepsy in autism (instead of a few neurons firing the whole brain can be set off) FROM CLARA FLANAGAN: EARLY SOCIALISATION: - Monkey Experiment: - Harry Harlow devised an experiment where single infants monkeys were caged with two dummy ‘mothers’ for the first eight months of their lives - One dummy was made out of wire-mesh cylinder with a monkey like face with a feeding bottle and the other covered in a cloth but had no feeding bottle - Harlow found monkeys only went to mother with food when they were hungry but spent most time with their cloth mother - Monkeys received only a poor version of body contact, which lacked interaction and grew up to be socially maladjusted and displayed autistic-like behaviours - Can neglect in childhood lead to misdiagnosis of learning difficulties like autism? - The development of attachment behaviour: - Schaffer and Emerson suggested a stage of theory of attachment development under the following headings - The asocial stage, Indiscriminate attachments, Specific attachments, Multiple attachments - Children Reared in Isolation: - When Genie was 13 her mother sought help for her - Her father believed she had a learning disability so locked her away, describing her as ‘retarded’ - At 13, she looked half her age and was physically, emotionally and cognitively underdeveloped - Her recovery was unsettled time by carers who abused her further - One notably autistic feature of her behaviour was a disinterest in other people, she didn’t reject them but treated them the same as an inanimate object - Did autism come first, or did the abuse lead to this? - Can this isolation cause autism or does it cause just ‘symptoms’ of autism? Cattaneo et al. - Inflammation and neuronal plasticity: a link between childhood trauma and depression pathogenesis - Brain-Derived Neurotrophic Factor (BDNF), have emerged as important mediators for long-term functional deterioration associated with mental illness - In depressed subjected, expression of BDNF is reduced in brain structures like the hippocampus - this represents anatomical targets for stress-induced structural changes - Studies show that chronic stress and genetic models of depression lead to reduced BDNF levels, contributing to behavioral dysfunction and depression symptoms. BDNF is also linked to resilience to stress and coping mechanisms. - Antidepressants can restore neuronal plasticity by modulating BDNF - BDNF plays a crucial role in neurogenesis (the formation of new neurons) - this process is often disrupted in depression. - early life trauma like childhood abuse can lead to long-term reductions in BDNF & impair neurogenesis, increasing vulnerability to depression From: BPS Society Limbic System Dysregulation: Overactivation of the amygdala in response to perceived threats, even in neutral situations, reduces the frontal lobe's ability to regulate threat perception. Stress can lead to reduced hippocampal volume, affecting memory consolidation and the ability to distinguish between genuine threats and false alarms. Childhood Adversity and Social Cognition: Childhood adversity (e.g., abuse, neglect) negatively impacts the ability to recognize emotions and intentions, observed in both patient and healthy groups. Physical neglect, more than emotional adversity, is the strongest predictor of impaired social cognition. This is mediated by poorer maternal care and unmet physical needs, leading to developmental challenges as per attachment theory. Social Cognition Mechanisms: Poor emotion recognition linked to inadequate maternal care stems from lack of a secure base for social exploration, leading to biases and fundamental impairments in social cognition. Role of the Default Mode Network (DMN): The DMN, active during rest, supports autobiographical memory, social reasoning, and Theory of Mind (ToM). Its connectivity follows an inverse U-shaped pattern, peaking in adulthood. Childhood adversity is linked to reduced DMN connectivity, especially between posterior regions, which mediates deficits in emotion recognition tasks. This dysconnectivity is observed regardless of diagnosis and without external cognitive tasks, indicating its fundamental role in social cognition challenges. - Strong developmental aspect to the strength of connections within the DMN, finding evidence of an inverse U-shape across the lifespan, with stronger connectivity in the DMN in adults compared to children or elderly - Are observations between childhood adversity and social cognition partly mediated via changes within DMN?