The subjective experience of emotion: A fearful view. 
LeDoux, J. E. & Hofmann, S. G (2018)
Current Opinion in Behavioral Sciences, 19, 67–72.
doi:10.1016/j.cobeha.2017.09.011.

Abstract

The subjective emotional experience, the feeling, is the essence of an emotion.
Objective manifestations in behaviour and in body or brain physiology are, at best, indirect indicators of these inner experiences.
The most direct way to assess conscious emotional feelings is through verbal self-report.

Because behavioural and physiological responses are important contributors to emotions, and the circuits underlying these are highly conserved, studies of animals have an important role in understanding how emotions are expressed and regulated in the brain.

Measuring subjective experiences

Scientific assessments of inner experiences require some form of self-reporting.
People can typically give either a verbal or a nonverbal report of information to which they have introspective access, but cannot provide a verbal report of information that is only processed non-consciously.

Verbal self-report remains the gold standard in studies of consciousness.
It is most suitable for assessing the content of immediate experiences rather than remembered experiences.
It is less useful for assessing the motivations underlying actions.

Contemporary views of subjective emotional experiences in relation to brain circuits

The neuro-Darwinian Approach: subjective fear is an innate state of mind inherited from animal ancestors

Darwin defined emotions as innate ‘states of mind’ that humans have inherited from animal ancestors, and that, when aroused, cause the expression of so-called emotional behaviours.

Neuroscience proponent
Views emotions as subjective feelings that emerge from a subcortical neural circuit that is highly conserved across mammals, including humans.
The circuit is centered on the amygdala and related subcortical areas.
The amygdala circuit, when activated by a threat to well being, both gives rise to fearful feelings and controls innate behaviours and supporting physiological responses that help the organism defend against harm.
Cognitive elaboration of subcortical fear by higher-cortical prefrontal circuits makes possible introspection and verbal reports of fear in humans. The core of fear is the inherited mental state arising from the subcortical circuit.

Problematic for this view is the evidence suggesting that the experience of fear is not embodied in the amygdala.
The amygdala can respond to threats without the person knowing the threat is present and without feeling fear.
Also, fear can be experienced when the amygdala is damaged.
Medications can change behavioural responses to threats without changing the subjective feeling.
The amygdala controls behavioural responses to threats, it does not seem to be directly responsible for the subjective experience of fear.

The neuro-Jamesian approach: subjective fear is a consequence form body responses

Fear and other emotional experiences result by way of feedback from the act of responding.
Fear results as a consequence of responses.

Fearful and other emotional feelings are the result of activity in body sensing circuits in the neocortex (somato-sensory and/or insula areas) that represent body states.
Cognitive elaboration by higher-cortical circuits allows introspection and self-reporting about these states.

Evidence that these representations of body states are the main causes of emotional experiences is lacking.

The neuro-behaviourist approach: subjective fear is a folk psychological construct that should be replaced by a scientific approach

In the early 20^th century, behaviourists eliminated mental states from the causal chain between external stimuli and behavioural response.
But they retained mental state terms when describing the empirical relation between stimuli and responses.

Fear became a hypothetical physiological state (central state), that connects threats with defensive behaviours.
Ultimately, the amygdala emerged as the locus of the central fear state.

Many who call upon the central state view today are ambivalent about the extent to which fear means subjective fear or a non-subjective state.
Adherents of a strong version of the position argue that subjective, conscious fear is an inaccurate scientific construct that can be replaced with a more rigorous scientific notion of fear as a non-subjective state of the amygdala-centred circuits.
The lack of correlation between verbal reports and amygdala activity is in this view due to the lack of access to amygdala activity by cognitive-based introspection.
Verbal report of subjective experience is viewed as a less desirable way of assessing fear than simply measuring amygdala-controlled responses.

The mechanistic reason a threat elicits defence responses is because it activates cells and synapses in circuits that control those responses.
The fear construct is superfluous in this context. It adds conceptual baggage that reifies fear and imbues the circuit with the exact phenomenological properties that are trying to be avoided.
The way to avoid these problems is by using non-subjective terminology to name the non-subjective central states.
But, it leaves open the question of how conscious fear comes about.

The neuro-cognitive approach: subjective fear emerges from higher-order processing

Emotional experiences result when we interpret physiological arousal in the brain and/or body in light of cognitive assessments of social situations, allowing the categorization and labelling of the experience.
Emotional experiences are cognitive constructions based on conceptualizations of situations or higher-order states that emerge as a result of the cognitive integration in working memory of diverse sources of information from within the brain and body.

A general network of cognitions underlies both cognitive and emotional states of consciousness.
What distinguishes cognitive and emotional states of consciousness, is the kind of inputs processed.
The consequence of defensive survival circuit activation contribute indirectly to the experience of fear but do not determine it.
Fear is the cognitive assessment that you are in harms way, a view that allows fear to arise from activity in any survival circuits or by existential concerns, in addition to predatory-related dangers that trigger the defensive survival circuit.

Conscious feelings in clinical assessment

Despite the centrality of introspection and cognitive processes in human mental life, subjective report never reached a central status in CBT.
Self-report has been seen as an easy but unreliable way to measure anxiety and fear.

Today, CBT therapists routinely use subjective patient report as part of treatment.
Its value continues to be debated.
The reduction in reported fear ratings during an exposure session is a crucial factor that determines the success of treatment.

Subjective reports of fear and anxiety are not unreliable proxy measures of fear and anxiety.
They are the best direct, and, at least so far, the only measures easily accessible for clinicians to assess the efficacy of treatment.
Therapists need to carefully listen to the clients’ report about their emotional states, further develop reliable assessment instruments of subjective reports, and utilize verbal strategies to elicit and modify them.
This must be done after other approaches to dampen the amygdala central state, which indirectly affects subjective experience