Introduction

I write as a psychoanalyst trained in the Freudian tradition (at the Institute of Psychoanalysis in London, which also entails the Kleinian tradition). I do not have expertise in other forms of psychotherapy. I was pleased to be invited to comment on this paper mainly because it is encouraging to see that such topics are now being discussed in the pages of Behavioral and Brain Science (BBS), but especially because the authors of this paper do indeed seem to identify a core mechanism of change in psychotherapy. Moreover, they approach this mechanism from both a psychological and a physiological viewpoint. This seems to me the only sensible way to proceed when trying to discern laws concerning the mental apparatus, the part of nature that uniquely presents both as a bodily organ and as subjective experience. The fact that it feels like something to be a brain has profound implications for how it works. Trying to understand the organ of the mind while excluding half of the available data has always been a fool's errand.

Prediction error

I have recently developed a theoretical formulation of the mechanism of psychotherapeutic change which is remarkably consonant with the one presented here by Lane et al (Solms Reference Solms2013; Reference Solms2014; Solms & Panksepp Reference Solms and Panksepp2012). Central to this formulation is something that is perhaps not sufficiently emphasised in the target article, namely the very purpose of learning and memory. Reminding ourselves of the biological purpose of learning and memory helps to make sense of the phenomenon of reconsolidation, which lies at the heart of the proposed mechanism of psychotherapy.

The purpose of memory is not to maintain veridical records of the past so much as to guide future behaviour on the basis of past experience. The purpose of learning is, in a word, to shape predictions, predictive models of reality, predictive models of how we can meet our needs in the world.

That is why memory functions implicitly for the most part; it serves no useful purpose to be consciously aware of the past basis of your present actions, so long as the actions in question bring about the predicted (desired) outcomes. In fact, conscious reflection upon an automatised motor programme undermines the intended behaviour because it destabilises the underlying programme. It becomes necessary to bring past experience to consciousness only when predicted outcomes fail to materialise, when prediction error occurs. Friston (Reference Friston2010) calls this “surprise.” Prediction error renders the basis of present actions salient again – and deserving of attention (of consciousness) once more – precisely because the prediction that was generated by the past learning episode is now in need of revision. Reconsolidation, then, simply improves prediction.

Biologically successful memories are reliable predictive algorithms – what Helmholtz (Reference Helmholtz and Southall1866) called “unconscious inferences.” There is no need for them to be conscious. In fact, as soon as they become conscious they no longer deserve to be called memories, because at that point they become labile again. This seems to be what Freud had in mind when he famously declared that “consciousness arises instead of a memory-trace” (Freud Reference Freud and Strachey1920, p. 25). The two states – consciousness and memory – are mutually incompatible with each other. They cannot arise from the same neural assemblage at the same time.

Consciousness and affect

Our understanding of the purpose of explicit cognition, including conscious remembering, is deepened when we recognise that the most fundamental form of consciousness is affect (Freud Reference Freud and Strachey1895; Reference Freud and Strachey1900; Reference Freud and Strachey1911). This is not the place to set out the accumulated evidence for the view that consciousness consists essentially in upper brainstem and limbic activation of intrinsically unconscious thalamo-cortical representations (see Damasio Reference Damasio2010; Merker Reference Merker2007; Panksepp Reference Panksepp1998; Solms Reference Solms2013; Solms & Panksepp Reference Solms and Panksepp2012). Suffice it to say that the affective core of consciousness attributes meaning to experience, within a biological scale of values: “Is this new experience (this surprise), good or bad for my survival and reproductive success, and therefore, how do I respond to it?” The affective basis of consciousness explains why it (consciousness) is required to solve the biobehavioural problem of meeting our needs in unpredicted (or unpredictable) situations, and why it is superfluous in relation to successful predictive algorithms. This is also not the place to speculate about how the conversion of affect into representational consciousness occurs, through what both Freud and Friston – following Helmholtz – call “binding” of “free energy” (Carhart-Harris & Friston Reference Carhart-Harris and Friston2010; Freud Reference Freud and Strachey1911; Friston Reference Friston2010; see Solms Reference Solms2014).

Repression

Unconscious cognitive processes do not consist only in viable predictive algorithms. Although it is true that the ultimate aim of learning is the generation of perfect predictive models – a state of affairs in which there is no need for consciousness (Nirvana) – the complexity of life is such that this ideal is unattainable. Real life teems with uncertainty and surprise, and therefore with consciousness. That is to say, it teems with unsolved problems. As a result, we frequently have to automatise less-than-perfect predictive algorithms so that we can get on with the job of living, considering the limited capacity of consciousness (Bargh Reference Bargh2014). Many behavioural programmes therefore have to be automatised – rendered unconscious – before they adequately predict how to meet our needs in the world. This applies especially to predictions generated in childhood, when it is impossible for us to achieve the things we want – when there is so much about reality that we cannot master.

The consequently rampant necessity for premature automatisation is, I believe, the basis of what Freud called “repression.” I hope this makes clear why repressed memories are always threatening to return to consciousness. They do not square with reality. They give rise to constant “surprise,” for example, in the transference. I hope this also clarifies why the repressed part of the unconscious is the part of the mind that most urgently demands reconsolidation, and therefore most richly rewards psychotherapeutic attention.