Introspection Is Signal Detection

Towards characterizing the canonical computations generating phenomenal experience

“…It has recently been discussed how introspection can be described as a signal detection process, i.e. a process which 'detects' the presence of meaningful signals in one's own internal representations and thus delivers them to a conscious experiencer (Morales, 2021). However, the "aboutness" property means that metacognitive evaluation has access to much more than a scalar estimate of the 'strength' (amplitude) of an internal representation about an external environmental property, for example.…”

“…Note that this isn't a statement about their 7 It is interesting to consider that sensory qualia are defined as sensory only insofar as they possess modality-specific qualia which we can link to a certain sensory apparatus such as vision, audition, interoception, vestibular sensation, and so on. However, it is possible that cognitive or emotional qualia also result from an introspective "signal detection" process (Morales, 2021) and are only distinguished from sensory modalities in these labels. This interesting discussion is beyond the scope of the present paper, however.…”

“…If these dimensions might be linked to modality-specific qualitative experiences, then they might just as easily be representative also of amodal or cross-modal experiences such as intensity or mental strength (Morales, 2018). A systematic characterization of 𝑦 and the functional form of 𝑔(⋅) could therefore also reveal which dimension(s) of 𝑦 may map onto amodal mental strength or vividness, identifying the dimensions along which introspection could operate like an internal signal detection process (Morales, 2021). Characterizing the distribution of 𝑦 through M-STEP could thus link introspective signal detection theory (Morales, 2021), perceptual reality monitoring (Lau, 2019), and conceptual approaches to awareness based on machine learning methods (Bengio, 2017;Gershman, 2019).…”

Identifying content-invariant neural signatures of perceptual vividness

“…We may experience the sound of birds calling outside our window more vividly from one day to the next, for example, and the smell of wild garlic can occupy a large portion of our experience on one walk but not another. This feature of consciousness has been described as the 'force and liveliness' of an experience (Hume, 2000), its 'magnitude' (Bartoshuk et al, 1986;Marks et al, 1988), and its 'mental strength' (Morales, 2018(Morales, , 2021. Put simply, these terms reflect the degree to which something takes up one's stream of consciousness: the phenomenal magnitude of experience.…”

“…The drivers of such content-independent signals may include changes in attention, emotion, and other cognitive factors that go beyond stimulus-specific salience, but nevertheless also contribute to the magnitude of experiences. As such, an alternative hypothesis is that rather than being bound to content-specific representations, phenomenal magnitude is encoded in a domain-general fashion, independently of stimulus content (Morales, 2021), with higher-order brain regions responsible for generating such signals.…”