Biobehavioural synchrony

In utero and postpartum, mother and baby are physiologically entrained, with patterns of heartbeat, hypothalamic–pituitary–adrenal activation and oxytocin levels mirroring and responding to one another.Reference Feldman⁴ These form the basis of parental sensitivity, identified by attachment theory's co-founder Ainsworth as the defining feature of secure attachments. Security-providing parents intuitively know and are rewarded by their infants, skilfully regulating – neither controlling nor ignoring – their needs and affects. For insecure caregivers, negative affects in their own children and others evoke rejection and diminished oxytocin reward. ClinicalReference Strathearn, Fonagy, Amico and Montague⁵ and animalReference Rincon-Cortes and Sullivan⁶ models show that attachment trauma in early life influences the developing brain with long-term psychopathological consequences, including the capacity to care for the next generation – a strong message for clinicians to focus on early life experiences, taking the history of the parents alongside that of the children.

Studies of the physiology of therapist–client attachment are scant, but it is likely that biobehavioural synchrony also plays a significant role in the success of psychotherapy, especially at mutative moments in sessions. Therapists vary widely in their effectiveness:Reference Wilson, Hayes, Biglan and Embry⁷ like insecure mothers,Reference Beebe and Lachmann⁸ they can ‘loom’ intrusively with over-empathic responses or make cuttingly dismissive interpretations, however seemingly accurate. AIP skills include the ability to recognise that threat – including in the consulting room – triggers attachment behaviour and is incompatible with emotional exploration and to co-regulate affective states of hyper- or hypo-arousal.Reference Slade⁹

Sensitive periods

Lorenz'sReference Lorenz¹⁰ concept of sensitive periods describes temporal windows in which the young of prosocial species bond with their parents. Bowlby was puzzled that no such clearly defined periods are found in humans. However, recent studies have shown that in both human and other mammalian species there are phases in which infants are especially susceptible to parental influence,Reference Tottenham, Anderson and Pine¹¹ when rapid learning takes place and the fear associated with novelty neutralised. In insecure attachment, sensitive periods tend to be disrupted. This is especially salient in disorganised attachment, associated with later psychopathology,Reference Lyons-Ruth, Jacobvitz, Cassidy and Shaver¹² in which ineffective self-soothing strategies – self-harm, addictions, eating disorders or dissociative disorders – reflect the absence of a modulating ‘secure base’ presence. In effective psychotherapy, a sensitive period re-opens in which the client becomes once more susceptible to support and influence. However, with this goes a degree of regression, the management of which is part of the art of therapy.

The Bayesian brain

Bayes, one of the founders of probability theory, described how when faced with uncertainty – drawing on the default mode network – ‘prior’ probabilities are assigned to future events, to be converted to ‘posteriors’ as predictions are updated in the light of experience. Computational psychiatry, pastReference Hemsley and Garety¹³ and present,Reference Debbane, Salaminios, Luyten, Badoud, Armando and Solida Tozzi¹⁴ draws on Bayesian ideas to understand psychopathology. The mathematician and psychiatrist FristonReference Friston¹⁵ extends Bayes' principle: the brain's aim, via ‘active inference’, is to reduce ‘surprise’ by converting ‘free’ – and therefore potentially disruptive and chaotic – informational energy into ‘bound’ form. ‘Bottom-up’ sensations are aligned with ‘top-down’ preconceptions and the degree of mismatch computed. Predictions need continuous updating lest we be forever trapped in the past, i.e. shaped by transference-dominated anachronistic assumptions. In healthy functioning, active inference minimises prediction error by (a) tolerating, while working to reduce, uncertainty; (b) active exploration aimed at improved sensory precision; and (c) updating of prior probabilities into more complex models of the self and its world.

Psychotherapy typically helps people at times of transition. Secure attachment makes the uncertainties of novelty tolerable, resolvable with the help of an attachment figure. In insecure attachment, agency is compromised, while rigid prior probabilities are clung to, either by isolationism or over-dependency. In a longer-term therapeutic relationship, as therapists’ and clients’ oxytocin systems become entrained, this cross-talks to the dopamine system. The ensuing ‘reward’ – the therapist's hope and love – opens up the complexity of psychological health in contrast to the simplistic splitting and projection. Revised assumptions become possible; inhibitions of action, feeling and thoughts are lifted.