•  3129
    The Neural Correlates of Consciousness
    with Hakwan Lau
    In Uriah Kriegel (ed.), The Oxford Handbook of the Philosophy of Consciousness, Oxford University Press. pp. 233-260. 2020.
    In this chapter, we discuss a selection of current views of the neural correlates of consciousness (NCC). We focus on the different predictions they make, in particular with respect to the role of prefrontal cortex (PFC) during visual experiences, which is an area of critical interest and some source of contention. Our discussion of these views focuses on the level of functional anatomy, rather than at the neuronal circuitry level. We take this approach because we currently understand more about…Read more
  •  2455
    Minority Reports: Consciousness and the Prefrontal Cortex
    Mind and Language 35 (4): 493-513. 2020.
    Whether the prefrontal cortex is part of the neural substrates of consciousness is currently debated. Against prefrontal theories of consciousness, many have argued that neural activity in the prefrontal cortex does not correlate with consciousness but with subjective reports. We defend prefrontal theories of consciousness against this argument. We surmise that the requirement for reports is not a satisfying explanation of the difference in neural activity between conscious and unconscious trial…Read more
  •  897
    Introspection Is Signal Detection
    British Journal for the Philosophy of Science. forthcoming.
    Introspection is a fundamental part of our mental lives. Nevertheless, its reliability and its underlying cognitive architecture have been widely disputed. Here, I propose a principled way to model introspection. By using time-tested principles from signal detection theory (SDT) and extrapolating them from perception to introspection, I offer a new framework for an introspective signal detection theory (iSDT). In SDT, the reliability of perceptual judgments is a function of the strength of an in…Read more
  •  776
    Confidence Tracks Consciousness
    with Hakwan Lau
    In Josh Weisberg (ed.), Qualitative Consciousness: Themes From the Philosophy of David Rosenthal, Cambridge University Press. pp. 91-105. 2022.
    Consciousness and confidence seem intimately related. Accordingly, some researchers use confidence ratings as a measure of, or proxy for, consciousness. Rosenthal discusses the potential connections between the two, and rejects confidence as a valid measure of consciousness. He argues that there are better alternatives to get at conscious experiences such as direct subjective reports of awareness (i.e. subjects’ reports of perceiving something or of the degree of visibility of a stimulus). In th…Read more
  •  614
    The Neural Substrates of Conscious Perception without Performance Confounds
    with Brian Odegaard and Brian Maniscalco
    In Felipe De Brigard & Walter Sinnott-Armstrong (eds.), Anthology of Neuroscience and Philosophy, . forthcoming.
    To find the neural substrates of consciousness, researchers compare subjects’ neural activity when they are aware of stimuli against neural activity when they are not aware. Ideally, to guarantee that the neural substrates of consciousness—and nothing but the neural substrates of consciousness—are isolated, the only difference between these two contrast conditions should be conscious awareness. Nevertheless, in practice, it is quite challenging to eliminate confounds and irrelevant differences b…Read more
  •  466
    Philosophy of perception in the psychologist's laboratory
    Current Directions in Psychological Science 32 (4): 307-317. 2023.
    Perception is our primary means of accessing the external world. What is the nature of this core mental process? Although this question is at the center of scientific research on perception, it has also long been explored by philosophers, who ask fundamental questions about our capacity to perceive: Do our different senses represent the world in commensurable ways? How much of our environment can we be aware of at one time? Which aspects of perception are ‘objective’, and which ‘subjective’? Wha…Read more
  •  462
    Controlling for performance capacity confounds in neuroimaging studies of conscious awareness
    with Jeffrey Chiang and Hakwan Lau
    Neuroscience of Consciousness 1 1-11. 2015.
    Studying the neural correlates of conscious awareness depends on a reliable comparison between activations associated with awareness and unawareness. One particularly difficult confound to remove is task performance capacity, i.e. the difference in performance between the conditions of interest. While ideally task performance capacity should be matched across different conditions, this is difficult to achieve experimentally. However, differences in performance could theoretically be corrected fo…Read more
  •  449
    Low attention impairs optimal incorporation of prior knowledge in perceptual decisions
    with Guillermo Solovey, Brian Maniscalco, Dobromir Rahnev, Floris P. de Lange, and Hakwan Lau
    Attention, Perception, and Psychophysics 77 (6): 2021-2036. 2015.
    When visual attention is directed away from a stimulus, neural processing is weak and strength and precision of sensory data decreases. From a computational perspective, in such situations observers should give more weight to prior expectations in order to behave optimally during a discrimination task. Here we test a signal detection theoretic model that counter-intuitively predicts subjects will do just the opposite in a discrimination task with two stimuli, one attended and one unattended: whe…Read more
  •  432
    Sustained Representation of Perspectival Shape
    with Axel Bax and Chaz Firestone
    Proceedings of the National Academy of Sciences of the United States of America 117 (26). 2020.
    Arguably the most foundational principle in perception research is that our experience of the world goes beyond the retinal image; we perceive the distal environment itself, not the proximal stimulation it causes. Shape may be the paradigm case of such “unconscious inference”: When a coin is rotated in depth, we infer the circular object it truly is, discarding the perspectival ellipse projected on our eyes. But is this really the fate of such perspectival shapes? Or does a tilted coin retain an…Read more
  •  364
    Measuring away an attentional confound?
    with Yasha Mouradi, Claire Sergent, Ned Block, Vincent Taschereau-Dumouchel, David Rosenthal, Piercesare Grimaldi, and Hakwan Lau
    Neuroscience of Consciousness 3 (1): 1-3. 2017.
    A recent fMRI study by Webb et al. (Cortical networks involved in visual awareness independent of visual attention, Proc Natl Acad Sci U S A 2016;113:13923–28) proposes a new method for finding the neural correlates of awareness by matching atten- tion across awareness conditions. The experimental design, however, seems at odds with known features of attention. We highlight logical and methodological points that are critical when trying to disentangle attention and awareness.
  •  361
    Empirical evidence for perspectival similarity
    Psychological Review 1 (1): 311-320. 2023.
    When a circular coin is rotated in depth, is there any sense in which it comes to resemble an ellipse? While this question is at the center of a rich and divided philosophical tradition (with some scholars answering affirmatively and some negatively), Morales et al. (2020, 2021) took an empirical approach, reporting 10 experiments whose results favor such perspectival similarity. Recently, Burge and Burge (2022) offered a vigorous critique of this work, objecting to its approach and conclusions …Read more
  •  273
    Mental Strength: A Theory of Experience Intensity
    Philosophical Perspectives 37 (1): 1-21. 2023.
    Our pains can be more or less intense, our mental imagery can be more or less vivid, our perceptual experiences can be more or less striking. These degrees of intensity of conscious experiences are all manifestations of a phenomenal property I call mental strength. In this article, I argue that mental strength is a domain-general phenomenal magnitude; in other words, it is a phenomenal quantity shared by all conscious experiences that explains their degree of felt intensity. Mental strength has …Read more
  •  197
    Domain-general and Domain-specific Patterns of Activity Support Metacognition in Human Prefrontal Cortex
    with Hakwan Lau and Stephen M. Fleming
    The Journal of Neuroscience 38 (14): 3534-3546. 2018.
    Metacognition is the capacity to evaluate the success of one's own cognitive processes in various domains; for example, memory and perception. It remains controversial whether metacognition relies on a domain-general resource that is applied to different tasks or if self-evaluative processes are domain specific. Here, we investigated this issue directly by examining the neural substrates engaged when metacognitive judgments were made by human participants of both sexes during perceptual and memo…Read more
  •  189
    Razonamiento Animal: Negación y Representaciones de Ausencia
    Revista Argentina de Ciencias Del Comportamiento 3 (1): 20-33. 2011.
    In this paper, I reject that animal reasoning, negation in particular, necessarily involves the representation of absences, as suggested by Bermúdez (2003, 2006, 2007), since this would still work as a logical negation (unavailable for non-linguistic creatures). False belief, pretense, and communication experiments show that non-human animals (at least some primates) have difficulties representing absent entities or properties. I offer an alternative account resorting to the sub-symbolic similar…Read more
  •  115
    Tracing the origins of consciousness
    Philosophical Psychology 36 (4): 767-771. 2023.
    Darwin’s theory is often illustrated with depictions of different finch beaks or with lined-up skeletons displaying subtle bone-structure changes throughout evolutionary history. In The Deep Histor...
  •  45
    The metaperceptual function: Exploring dissociations between confidence and task performance with type 2 psychometric curves
    with Brian Maniscalco, Olenka Graham Castaneda, Brian Odegaard, Sivananda Rajananda, and Megan Peters
    Confidence can dissociate from perceptual accuracy, suggesting distinct computational and neural processes underlie these psychological functions. Recent investigations have therefore sought to experimentally isolate metacognitive processes by creating conditions where perceptual sensitivity is matched but confidence differs (“matched-performance / different-confidence”; MPDC). Despite these endeavors’ success, much remains unknown about MPDC effects and how to best harness them in experimental …Read more