Complex human reasoning involves minimal abilities to extract conclusions implied in the available information. These abilities are considered “deductive” because they exemplify certain abstract relations among propositions or probabilities called deductive arguments. However, the electrophysiological dynamics which supports such complex cognitive pro- cesses has not been addressed yet. In this work we consider typically deductive logico- probabilistically valid inferences and aim to verify or refute their electrophysiological functional connectivity differences from invalid inferences with the same content (same relational variables, same (...) stimuli, same relevant and salient features). We recorded the brain electrophysiological activity of 20 participants (age 1⁄4 20.35 ± 3.23) by means of an MEG system during two consecutive reasoning tasks: a search task (invalid condition) without any specific deductive rules to follow, and a logically valid deductive task (valid condition) with explicit deductive rules as instructions. We calculated the functional connectivity (FC) for each condition and conducted a seed-based analysis in a set of cortical regions of interest. Finally, we used a cluster-based permutation test to compare the dif- ferences between logically valid and invalid conditions in terms of FC. As a first novel result we found higher FC for valid condition in beta band between regions of interest and left prefrontal, temporal, parietal, and cingulate structures. FC analysis allows a second novel result which is the definition of a propositional network with operculo-cingular, parietal and medial nodes, specifically including disputed medial deductive “core” areas. The experiment discloses measurable cortical processes which do not depend on content but on truth-functional propositional operators. These experimental novelties may contribute to understand the cortical bases of deductive processes. (shrink)

In order to improve our understanding of the components that reflect functionally important processes during reward anticipation and consumption, we used principle components analyses (PCA) to separate and quantify averaged ERP data obtained from each stage of a modified monetary incentive delay (MID) task. Although a small number of recent ERP studies have reported that reward and loss cues potentiate ERPs during anticipation, action preparation, and consummatory stages of reward processing, these findings are inconsistent due to temporal and spatial overlap (...) between the relevant electrophysiological components. Our results show three components following cue presentation are sensitive to incentive cues (N1, P3a, P3b). In contrast to previous research, reward‐related enhancement occurred only in the P3b, with earlier components more sensitive to break‐even and loss cues. During feedback anticipation, we observed a lateralized centroparietal negativity that was sensitive to response hand but not cue type. We also show that use of PCA on ERPs reflecting reward consumption successfully separates the reward positivity from the independently modulated feedback‐P3. Last, we observe for the first time a new reward consumption component: a late negativity distributed over the left frontal pole. This component appears to be sensitive to response hand, especially in the context of monetary gain. These results illustrate that the time course and sensitivities of electrophysiological activity that follows incentive cues do not follow a simple heuristic in which reward incentive cues produce enhanced activity at all stages and substages. (shrink)

The German pioneer of electrophysiology, Emil du Bois-Reymond (1818–1896), is generally assumed to have remained silent on the subject of the brain. However, the archive of his papers in Berlin contains manuscript notes to a lecture on “The Seat of the Soul” that he delivered to popular audiences in 1884 and 1885. These notes demonstrate that cerebral localization and brain function in general had been concerns of his for quite some time, and that he did not shy away from (...) these subjects. (shrink)

A central debate in philosophy and neuroscience pertains to whether PFC activity plays an essential role in the neural basis of consciousness. Neuroimaging and electrophysiology studies have revealed that the contents of conscious perceptual experience can be successfully decoded from PFC activity, but these findings might be confounded by post- perceptual cognitive processes, such as thinking, reasoning, and decision-making, that are not necessary for con- sciousness. To clarify the involvement of the PFC in consciousness, we present a synthesis of (...) research that has used intracranial electrical stimulation (iES) for the causal modulation of neural activity in the human PFC. This research provides compelling evidence that iES of only certain prefrontal regions (i.e., orbitofrontal cortex and anterior cingu- late cortex) reliably perturbs conscious experience. Conversely, stimulation of anterolateral prefrontal sites, often con- sidered crucial in higher-order and global workspace theories of consciousness, seldom elicits any reportable alterations in consciousness. Furthermore, the wide variety of iES-elicited effects in the PFC (e.g., emotions, thoughts, and olfactory and visual hallucinations) exhibits no clear relation to the immediate environment. Therefore, there is no evidence for the kinds of alterations in ongoing perceptual experience that would be predicted by higher-order or global workspace theories. Nevertheless, effects in the orbitofrontal and anterior cingulate cortices suggest a specific role for these PFC subregions in supporting emotional aspects of conscious experience. Overall, this evidence presents a challenge for higher-order and global workspace theories, which commonly point to the PFC as the basis for con- scious perception based on correlative and possibly confounded information. (shrink)

The concept of the cortical column refers to vertical cell bands with similar response properties, which were initially observed by Vernon Mountcastle’s mapping of single cell recordings in the cat somatic cortex. It has subsequently guided over 50 years of neuroscientific research, in which fundamental questions about the modularity of the cortex and basic principles of sensory information processing were empirically investigated. Nevertheless, the status of the column remains controversial today, as skeptical commentators proclaim that the vertical cell bands are (...) a functionally insignificant by-product of ontogenetic development. This paper inquires how the column came to be viewed as an elementary unit of the cortex from Mountcastle’s discovery in 1955 until David Hubel and Torsten Wiesel’s reception of the Nobel Prize in 1981. I first argue that Mountcastle’s vertical electrode recordings served as criteria for applying the column concept to electrophysiological data. In contrast to previous authors, I claim that this move from electrophysiological data to the phenomenon of columnar responses was concept-laden, but not theory-laden. In the second part of the paper, I argue that Mountcastle’s criteria provided Hubel Wiesel with a conceptual outlook, i.e. it allowed them to anticipate columnar patterns in the cat and macaque visual cortex. I argue that in the late 1970s, this outlook only briefly took a form that one could call a ‘theory’ of the cerebral cortex, before new experimental techniques started to diversify column research. I end by showing how this account of early column research fits into a larger project that follows the conceptual development of the column into the present. (shrink)

The primary focus of this project is the silent and subvocal speech-recognition interface unveiled in 2018 as an ambulatory device wearable on the neck that detects a myoelectrical signature by electrodes worn on the surface of the face, throat, and neck. These emerge from an alleged “intending to speak” by the wearer silently-saying-something-to-oneself. This inner voice is believed to occur while one reads in silence or mentally talks to oneself. The artifice does not require spoken sounds, opening the mouth, or (...) any explicit or external movement of the lips. The essay then considers such subvocal “speech” as a mode of writing or saying and the interior of the mouth or oral cavity as its writing surface. It briefly revisits discussions of telepathy to recontextualize Heidegger’s warning against enframing language exclusively within calculative technics and physiology, which he suggests is detrimental to Mundarten (mouth-modes of regional dialects). It closes in reconsideration of Husserl’s phenomenology of language and meaning in Ideas as it might apply to subvocal speech-recognition interfaces. It suggests ways by which the electrophysiology that the device detects and deciphers (as an alleged intention of a presumed natural language unspoken vocally or aloud) might supplement Husserl’s insinuation of the Leiblichkeit of language through a self-stamping extraction of an extension of meaning. (shrink)

In traditional formal semantics the notions of reference, truth and satisfaction are basic and that of representation is derivative and dispensable. If a level of representation is included in the formal presentation of the theory, it is included as a heuristic. Semantics in the traditional sense has no bearing on any form of mental processing. When reference is understood within this framework, cognitive neuroscience cannot possibly provide any insights into the nature of reference. Traditional semantics, however, has numerous shortcomings that (...) render it inadequate as an account of natural language. Dynamic semantic theories, such as discourse representation theory (DRT), treat ever­growing, revisable mental representations as the basic semantic entities. Within this framework, there are two central notions of reference. New information may refer back to previously introduced discourse referents and discourse referents may refer to worldly entities. Because DRT treats mental representations as indispensable elements of the theory, evidence from neuroscience, particularly the recording of electroencephalograms (EEG) and its derivative event-­related potentials (ERPs), can reasonably be thought to shed light on meaning and reference within this framework. In this chapter I first review the advantages of DRT in accommodating linguistic data and then review data from neuroscience that seem to support it. Finally, I consider some methodological concerns that have been raised about the neuroscientific approach to semantics. (shrink)

Objective: This study aimed to determine the diagnostic value of median nerve cross-sectional area (MNCSA; mm2), which can be measured using ultrasonography (US), compared with electrophysiological parameters in patients with mild and moderate carpal tunnel syndrome (CTS). Methods: The study included 72 wrists of 25 patients with CTS diagnosis and 23 healthy controls. Median and ulnar sensory and motor nerve conduction study results and MNCSA values determined by US, of all subjects were recorded. Electrophysiological and US data of the patient (...) and control groups were compared, and a correlation between MNCSA and velocity and latency of sensory and motor conduction of median nerves was investigated. Moreover, Receiver operating characteristic ROC curve analysis was performed to determine the cut-off value for diagnosing CTS with MNCSA. Differences between the mean MNCSA values, median nerve sensory conduction velocity (SCV), and motor distal latency (MDL) were statistically significant between the groups. Results: Differences between the mean MNCSA values of grade 1 CTS patients with very mild CTS and those of the healthy controls were statistically significant. There was a moderate and significant negative correlation between MNCSA and SCV values and a low and significant positive correlation between MNCSA and MDL values. In addition, there was a moderate and significant positive correlation between MNCSA values and grades. A cut-off value of 10.25 mm2, which was obtained by the ROC analysis, enabled the differentiation of patients and controls with a sensitivity of 80% and specificity of 76%. Conclusion: We suggest that MNCSA, which is calculated using US, has high sensitivity and specificity values and is used as a firstline diagnostic tool with electromyography. (shrink)

This essay considers a long-standing controversy between two nineteenth century pioneers in electrophysiology: the German scientist Emil du Bois-Reymond (1818-1896), and his Italian rival Carlo Matteucci (1811-1868). Historians have generally described their disagreement in du Bois-Reymond’s terms: the product of a contrast in scientific outlook. While not discounting this interpretation, I want to suggest that the controversy was driven as much by the rivals’ similarity as it was by their difference.

Increasing behavioural evidence suggests that expert video game players (VGPs) show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG) recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT) in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and (...) maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years). Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented). IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction. (shrink)

Given the hard problem of consciousness, there are no brain electrophysiological correlates of the subjective experience (the felt quality of redness or the redness of red, the experience of dark and light, the quality of depth in a visual field, the sound of a clarinet, the smell of mothball, bodily sensations from pains to orgasms, mental images that are conjured up internally, the felt quality of emotion, the experience of a stream of conscious thought, or the phenomenology of thought). However, (...) there are occipital and left temporal brain electrophysiological correlates of the subjective experience. Notwithstanding, as an evoked signal, the change in event-related brain potential phase (frequency is the change in phase over time) is instantaneous, that is, the frequency will transiently be infinite: a transient peak in frequency (positive or negative), if any, is instantaneous in electroencephalogram averaging or filtering that the event-related brain potentials required and the underlying structure of the event-related brain potentials in the frequency domain cannot be accounted for, for example, by the Wavelet Transform or the Fast Fourier Transform analysis, because they require that frequency be derived by convolution rather than by differentiation. However, as I show, one suitable method for analysing the instantaneous change in event-related brain potential phase and accounting for a transient peak in frequency (positive or negative), if any, in the underlying structure of the event-related brain potentials is the Empirical Mode Decomposition with post-processing Ensemble Empirical Mode Decomposition. (shrink)

This paper employs a case study from the history of neuroscience—brain reward function—to scrutinize the inductive argument for the so-called ‘Heuristic Identity Theory’ (HIT). The case fails to support HIT, illustrating why other case studies previously thought to provide empirical support for HIT also fold under scrutiny. After distinguishing two different ways of understanding the types of identity claims presupposed by HIT and considering other conceptual problems, we conclude that HIT is not an alternative to the traditional identity theory so (...) much as a relabeling of previously discussed strategies for mechanistic discovery. (shrink)