Philosophy · Psychology · Neuroscience
I'm a Provost's Postdoctoral Fellow in the Department of Psychological and Brain Sciences at Johns Hopkins University, where I do research in philosophy and philosophy-inspired psychology in Chaz Firestone's lab.
My research focuses on the subjective character of the mind, and draws on philosophy, psychology, and neuroscience. The goal of my work is to understand the nature of conscious experiences as well as the psychological and neural processes that give rise to them. In particular, I focus on understanding how subjectivity affects what we experience and what we take ourselves to be experiencing. To this end, I study how perceptual, cognitive and social idiosyncrasies shape our experiences. I also study the metacognitive and introspective mechanisms that allow us to know our own minds and how to best calibrate them.
Before coming to Johns Hopkins, I completed a Ph.D. in Philosophy at Columbia University under the supervision of John Morrison. During my time there, I was an affiliate in Hakwan Lau's Lab (Columbia/UCLA) where I worked on metacognition, attention and perceptual awareness using diverse methods that included psychophysics, fMRI (with Steve Fleming) and theoretical approaches.
When not doing philosophy or science, I enjoy spending time with my wife and friends, and also walking around with my camera.
9. Phillips, I. & MORALES, J. (Forthcoming) The Fundamental Problem with No-Cognition Paradigms. Trends in Cognitive Sciences
Abstract: We argue that, while Ned Block's new criticism of no-report paradigms for finding the neural correlates of consciousness is reasonable, his proposal for no-cognition paradigms—in particular his appeal to Brascamp et al. (2015)'s binocular rivalry paradigm—cannot be used to find the neural correlates of consciousness.
Abstract: 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 trials, and that prefrontal theories of consciousness come out of this debate unscathed.
This paper is being featured in the Brains Blog's Mind & Language Symposium this week (December 2-6, 2019) with commentaries by Liz Irvine, Benji Kozuch, and Michael Pitts & Kevin Ortego. Here's our response to their commentaries. And you can comment too!
7. MORALES, J., Lau, H., & Fleming, S. (2018) Domain-general and Domain-specific Patterns of Activity Support Metacognition in Human Prefrontal Cortex. The Journal of Neuroscience 38(14): 3534-3546. open access
Abstract: 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 memory tasks matched for stimulus and performance characteristics. By comparing patterns of fMRI activity while subjects evaluated their performance, we revealed both domain-specific and domain-general metacognitive representations. Multivoxel activity patterns in anterior prefrontal cortex predicted levels of confidence in a domain-specific fashion, whereas domain-general signals predicting confidence and accuracy were found in a widespread network in the frontal and posterior midline. The demonstration of domain-specific metacognitive representations suggests the presence of a content-rich mechanism available to introspection and cognitive control.
6. MORALES, J., Mouradi Y., Sergent C., Block N., Taschereau-Dumouchel, V., Rosenthal,D., Grimaldi, P. & Lau, H. (2017) Measuring Away an Attentional Confound?Neuroscience of Consciousness, 3(1): 1-3. open access
Abstract: 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 attention 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.
Abstract: 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 for mathematically. One such proposal is found in a recent paper by Lamy, Salti and Bar-Haim [Lamy D, Salti M, Bar-Haim Y. Neural correlates of subjective awareness and unconscious processing: an ERP study. J Cognitive Neurosci 2009,21:1435-46], who put forward a corrective method for an electroencephalography experiment. We argue that their analysis is essentially grounded in a version of High Threshold Theory, which has been shown to be inferior in general to Signal Detection Theory. We show through a series of computer simulations that their correction method only partially removes the influence of performance capacity, which can yield misleading results. We present a mathematical correction method based on Signal Detection Theory that is theoretically capable of removing performance capacity confounds. We discuss the limitations of mathematically correcting for performance capacity confounds in imaging studies and its impact for theories about consciousness.
4. MORALES, J., Solovey, G., Maniscalco, B., Rahnev, D., de Lange, F. P., & Lau, H. (2015) Low Attention Impairs Optimal Incorporation of Prior Knowledge in Perceptual decisions. Attention, Perception & Psychophysics, 77(6): 2021–2036. open access
Abstract: 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: when subjects are probed to discriminate the unattended stimulus, they rely less on prior information about the probed stimulus’ identity. The model is in part inspired by recent findings that attention reduces trial-by-trial variability of the neuronal population response and that they use a common criterion for attended and unattended trials. In five different visual discrimination experiments, when attention was directed away from the target stimulus, subjects did not adjust their response bias in reaction to a change in stimulus presentation frequency despite being fully informed and despite the presence of performance feedback and monetary and social incentives. This indicates that subjects did not rely more on the priors under conditions of inattention as would be predicted by a Bayes-optimal observer model. These results inform and constrain future models of Bayesian inference in the human brain.
Abstract: 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 similarity judgments proposed by Vigo & Allen (2009) and expectations: animal proto-negation takes place through the incompatibility between an expected and the actual representation. Finally, I propose that the expectation paradigm be extrapolated to other experi-ments in cognitive psychology (both with pre-linguistic children and animals) in order to design fair experiments that test other minds considering their true abilities. [In Spanish.]
2. MORALES, J., Odegaard, B. & Maniscalco, B. (Forthcoming). The Neural Substrates of Conscious Perception without Performance Confounds. In Anthology in Neuroscience and Philosophy (Eds. Felipe de Brigard & Walter Sinnott-Armstrong), MIT Press. preprint
Abstract: 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 between conscious and unconscious conditions. In particular, there is an often-neglected confound that is crucial to eliminate from neuroimaging studies: task performance. Unless subjects’ task performance is matched (and hence perceptual signal processing is matched), researchers risk finding the neural correlates of perception, rather than conscious perception. Here, we discuss the theoretical motivations for the performance matching framework and review empirical demonstrations of, and theoretical inferences derived from, obtaining differences in consciousness while controlling for task performance. We summarize signal detection theoretic modeling frameworks that explain how it is that we can derive performance-matched differences in consciousness without the effect being trivially driven by differences in criterion setting, and also provide principles for designing experimental paradigms that yield performance-matched differences in awareness. Finally, we address potential technical and theoretical issues that stem from matching performance across conditions of awareness, and we introduce the notion of “triangulation” for designing comprehensive experimental sets that can better reveal the neural substrates of consciousness.
Abstract: Current theories of the neural correlates of consciousness make rather different predictions about the role of prefrontal cortex during visual experiences. In this chapter, we focus on the predictions made by the Two-Visual-Systems Hypothesis, Local Recurrency Theory, Higher Order Theory, and Global Workspace Theory. Despite the apparent stark differences between conscious and unconscious perceptual processing, available neuroimaging, neurophysiological, and modelling evidence suggests that their neural substrates must be largely shared. This indicates that the difference in neural activity between conscious and unconscious perceptual processing is likely to be subtle and highly specialized. We argue that the Higher Order Neural Theory of consciousness is better poised to explain the current evidence by highlighting highly specific activity found in prefrontal cortex. An important consequence of this subtle difference between conscious and unconscious processes is that theories and imaging techniques that emphasize only marked differences between conscious and unconscious level of activity are likely to be insensitive to the relevant neural activity patterns that underlie conscious experiences in prefrontal cortex. Finally, the evidence we discuss suggests that the functional advantages of conscious over unconscious perceptual processing may be more limited than commonly thought.
Work in Progress
Philosophy of Perception
The Double Life of Shapes: The Persistence of Perspectival Representations
When the Brain Goes Haywire: Anti-Bayesian Updating in Perception (with Steven Gross and Chaz Firestone), in Expected Experiences: The Predictive Mind in an Uncertain World, Tony Cheng and Jakob Howhy (Eds.). (commissioned)
Philosophy of Mind
Mental Strength: The Degrees of Conscious Experience *under review
Introspection Is Signal Detection
Uncertainty Tracks Subjectivity (with Hakwan Lau), for Qualitative Consciousness: Themes from the Philosophy of David Rosenthal, ed. Josh Weisberg, Cambridge University Press (under contract)
Philosophy of Neuroscience
Decoding Fear: Advances in Decoded Neurofeedback & Challenges for the Philosopher and the Clinical Psychologist
A “Hot” Dilemma: Reports and Lesions in Prefrontal Cortex (with Matthias Michel & Brian Odegaard)
Does The World Look Flat? Sustained Representation of Perspectival Shape (with Chaz Firestone)
Social Stereotypes Impair Recognition of Incidental Visual Features (with Austin Baker & Chaz Firestone) * under review
The Functions of Consciousness: On the Initiation of Action (with Brian Maniscalco, Brian Odegaard & Megan Peters)
Morales, Lau & Fleming (2018) Domain-General and Domain-Specific Patterns of Activity Supporting Metacognition in Human Prefrontal Cortex. The Journal of Neuroscience 38 (14).
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Philosophy of Language & Mind | 2017 | summer
Symbolic Logic | 2016 | summer
Columbia Journey Seminar | CUSP | 2016-2018
Symbolic Logic | Achille Varzi | 2017 | spring
Methods and Problems of Philosophical Thought | David
Albert | 2016 | fall
Methods and Problems of Philosophical Thought | Jessica
Collins | 2012 | spring
Introduction to Logic | John Morrison | 2011 | fall
Philosophy of Perception (co-taught with Luis Xavier López
Farjeat | 2010 | spring
Minds, Brains & Behavior | 2009 | fall
Symbolic Logic | 2008, 2009-2010
History of Civilization | 2008-2010
Business Ethics | 2006-2008
History of Philosophy (Early Modern to Kant) | 2007-2010
History of Philosophy (Analytic Philosophy) | 2007-2010