Cognitive Neuroscience

Hanna, Jeff; Mejias, Sandrine; Schelstraete, Marie-Anne; Pulvermüller, Friedemann; Shtyrov, Yury; van der Lely, Heather K. J.

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2013.860087pmid: 24279717

Though activation of Broca’s region in the combinatorial processing of symbols (language, music) has been revealed by neurometabolic studies, most previous neurophysiological research found the earliest grammar indices in the temporal cortex, with inferior-frontal generators becoming active at relatively late stages. We use the attention- and task-free syntactic mismatch negativity (sMMN) event-related potential (ERP) to measure rapid and automatic sensitivity of the human brain to grammatical information in participants’ native language (French). Further, sources underlying the MMN were estimated by applying the Parametrical Empirical Bayesian (PEB) approach, with the Multiple Sparse Priors (MSP) technique. Results showed reliable grammar-related activation focused on Broca’s region already in the 150–190 ms time window, providing robust documentation of its involvement in the first stages of syntactic processing.

Vilberg, Kaia L.; Rugg, Michael D.

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2013.860088pmid: 24283400

We investigated whether time courses of fMRI BOLD activity in recollection-sensitive brain regions varied according to the time over which recollected information was maintained. Human subjects studied word-picture pairs and were subsequently tested with studied and unstudied pictures during a scanned test phase. The test requirement was to judge whether each picture was old or new and, if old, to retrieve its study associate and hold it in mind until a response cue appeared. The interval between the test item and cue varied between two and eight seconds. Separate responses were required when items were deemed new or the associate was not retrieved. Whereas recollection-related activity in the posterior cingulate, medial temporal, and medial prefrontal cortices was transient and unrelated to the maintenance interval, activity in the left anterior angular gyrus (aLAG) tracked the interval. Thus, as in a prior study, recollection-sensitive regions could be temporally dissociated.

Rumiati, Raffaella I.; Carnaghi, Andrea; Improta, Erika; Diez, Ana Laura; Silveri, Maria Caterina

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2013.876981pmid: 24423240

The most relevant evidence for the organization of the conceptual knowledge in the brain was first provided by the patterns of deficits in brain-damaged individuals affecting one or another semantic category. Patients with various etiologies showed a disproportionate impairment in producing and understanding names of either living (fruits, vegetables, animals) or nonliving things (tools, vehicles, clothes). These double dissociations between spared and impaired recognition of living and nonliving things led to suggest that these categories are discretely represented in the brain. Recently social groups were found to be represented independently of traditional living and nonliving categories. Here we tested 21 patients with different types of primary dementia with three word sorting tasks tapping their conceptual knowledge about living and nonliving entities and social groups. Patients double dissociated in categorizing words belonging to the three categories. These findings clarify that knowledge about social groups is distinct from other semantic categories.

Seth, Anil K.

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2013.877880pmid: 24446823

Normal perception involves experiencing objects within perceptual scenes as real, as existing in the world. This property of “perceptual presence” has motivated “sensorimotor theories” which understand perception to involve the mastery of sensorimotor contingencies. However, the mechanistic basis of sensorimotor contingencies and their mastery has remained unclear. Sensorimotor theory also struggles to explain instances of perception, such as synesthesia, that appear to lack perceptual presence and for which relevant sensorimotor contingencies are difficult to identify. On alternative “predictive processing” theories, perceptual content emerges from probabilistic inference on the external causes of sensory signals, however, this view has addressed neither the problem of perceptual presence nor synesthesia. Here, I describe a theory of predictive perception of sensorimotor contingencies which (1) accounts for perceptual presence in normal perception, as well as its absence in synesthesia, and (2) operationalizes the notion of sensorimotor contingencies and their mastery. The core idea is that generative models underlying perception incorporate explicitly counterfactual elements related to how sensory inputs would change on the basis of a broad repertoire of possible actions, even if those actions are not performed. These “counterfactually-rich” generative models encode sensorimotor contingencies related to repertoires of sensorimotor dependencies, with counterfactual richness determining the degree of perceptual presence associated with a stimulus. While the generative models underlying normal perception are typically counterfactually rich (reflecting a large repertoire of possible sensorimotor dependencies), those underlying synesthetic concurrents are hypothesized to be counterfactually poor. In addition to accounting for the phenomenology of synesthesia, the theory naturally accommodates phenomenological differences between a range of experiential states including dreaming, hallucination, and the like. It may also lead to a new view of the (in)determinacy of normal perception.

Friston, Karl

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.905517pmid: 24702520

AbstractI greatly enjoyed Seth’s compelling synthesis of sensorimotor contingencies and active inference. I would also like to thank Jim Hopkins for sending me the quote (below)—which speaks directly to the embodied nature of perceptual inference that underlies the perspectives reconciled in Seth (this issue). These perspectives include perception as hypothesis testing, affordance, and sensorimotor contingencies. This commentary briefly rehearses the fundaments of active inference and offers a formal basis for Seth’s key argument.

Gotts, Stephen J.; Martin, Alex

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.905518pmid: 24702431

AbstractIn his Discussion Paper, Seth makes the case for counterfactual richness of predictive processing models in explaining perceptual presence and its absence in synesthetic concurrent percepts. Here, we question the relevance of counterfactual richness for these and related phenomena, and we argue that alternative theories of perception that incorporate top-down/bottom-up facilitatory interactions are at no relative disadvantage in addressing them.

Metzinger, Thomas

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.905519pmid: 24702471

AbstractSeth develops a convincing and detailed internalist alternative to the sensorimotor-contingency theory of perceptual phenomenology. However, there are remaining conceptual problems due to a semantic ambiguity in the notion of “presence” and the idea of “subjective veridicality.” The current model should be integrated with the earlier idea that experiential “realness” and “mind-independence” are determined by the unavailability of earlier processing stages to attention. Counterfactual richness and attentional unavailability may both be indicators of the overall processing level currently achieved, a functional property that normally correlates with epistemic reliability. Perceptual presence as well as phenomenal transparency express epistemic reliability on the level of conscious processing.

van Leeuwen, Tessa M.

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.905520pmid: 24702569

AbstractA new theoretical framework (PPSMC) applicable to synesthesia has been proposed, in which the discrepancy between the perceptual reality of (some) synesthetic concurrents and their subjective non-veridicality is being explained. The PPSMC framework stresses the relevance of the phenomenology of synesthesia for synesthesia research—and beyond. When describing the emergence and persistence of synesthetic concurrents under PPSMC, it is proposed that precise, high-confidence priors are crucial in synesthesia. I discuss the construction of priors in synesthesia.

Froese, Tom

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.905521pmid: 24720582

AbstractSeth extends predictive processing with counterfactuals: Encoded probabilities of what would occur given a repertoire of possible (but unexecuted) actions. He thereby provides a neat mathematical formulation of the sensorimotor account of perceptual presence, i.e., of the fact that we perceive a whole object while being limited to seeing it from a perspective. Synesthetic concurrents are explained in terms of impoverished counterfactuals. I argue that this explanation misses its target, because it only accounts for a lack of objecthood. Enactive theory is better suited to explain concurrents’ lack of subjectivity veridicality. The world itself shapes experience only during veridical perception.

Hohwy, Jakob

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.906399pmid: 24720555

AbstractSeth’s counterfactual-based predictive processing account of presence is compelling and innovative; it gives a new, deeper understanding of a critical aspect of our phenomenology. Remaining in overall agreement with Seth’s use of the prediction error minimization framework, I consider the elusive concept of presence, I probe the exact role of counterfactuals in the phenomenology of presence, and I suggest that some aspects of sense of presence can be accounted for by hierarchical inference without direct appeal to predictive processing of sensorimotor contingencies.

Rouw, Romke; Ridderinkhof, K. Richard

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.906400pmid: 24735051

AbstractThis discussion paper forms an insightful addition to the synesthesia literature. Accompanying a steep increase in recent publications on synesthesia, it helps remedy the conspicuous paucity of mechanistic process models explaining the condition. The paper furthermore addresses what is arguably among the most interesting questions: Why do most synesthetes *not* get confused by their additional sensations? This is particularly interesting when phrased in a broader context: What are the mechanisms for deciding which of the sensations we experience reflect something “real” (phenomena in the outside world) and which reflect something that is “not real” (internally generated and private phenomena).

O’Regan, J. Kevin; Degenaar, Jan

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.907256pmid: 24742075

AbstractMastery of sensorimotor contingencies can be viewed as attunement to potentialities. In our view, these potentialities have wider application than recognized in Seth’s account of sensory presence, and should pertain to all of sensory experience. Instead of appealing only to a notion of counterfactual richness, we propose that the degree of sensory presence can be further specified in terms of bodiliness, insubordinateness, and grabbiness. While PPSMC can provide a possible implementation of a sensorimotor account of synesthesia, we suggest it should be rid of its representationalist interpretation.

Madary, Michael

2014 Cognitive Neuroscience

doi: 10.1080/17588928.2014.907257pmid: 24739124

AbstractIn this commentary, I suggest that non-visual perceptual modalities provide counterexamples to Seth’s claim that perceptual presence depends on counterfactual richness. Then I suggest a modification to Seth’s view that is not vulnerable to these counterexamples.