Hierarchical Bayesian inference in the visual cortex

Lee, Tai Sing; Mumford, David

doi:10.1364/josaa.20.001434

Cited by 1,265 publications

(1,117 citation statements)

References 58 publications

(125 reference statements)

Supporting

Mentioning

1,058

Contrasting

Order By: Relevance

“…Hierarchical Bayesian inference models, on the other hand, posit the opposite-that reduced activation at low levels is due to top-down suppression of inconsistent representations, while consistent information remains active (Lee & Mumford, 2003). Inhibitory feedback is thus implemented in both classes of models-predictive coding and Bayesian inference-but the information being suppressed differs.…”

Section: Discussionmentioning

confidence: 99%

Neural evidence for competition-mediated suppression in the perception of a single object

Cacciamani

Scalf

Peterson

2015

Cortex

View full text Add to dashboard Cite

. (2015) 'Neural evidence for competition-mediated suppression in the perception of a single ob ject. ', Cortex., Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Multiple objects compete for representation in visual cortex. Competition may also underlie the perception of a single object. Computational models implement object perception as competition between units on opposite sides of a border. The border is assigned to the winning side, which is perceived as an object (or " figure"), whereas the other side is perceived as a shapeless ground. Behavioral experiments suggest that the ground is inhibited to a degree that depends on the extent to which it competed for object status, and that this inhibition is relayed to low-level brain areas. Here, we used fMRI to assess activation for ground regions of task-irrelevant novel silhouettes presented in the left or right visual field (LVF or RVF) while participants performed a difficult task at fixation. Silhouettes were designed so that the insides would win the competition for object status. The outsides (grounds) suggested portions of familiar objects in half of the silhouettes and novel objects in the other half. Because matches to object memories affect the competition, these two types of silhouettes operationalized, respectively, high competition and low competition from the grounds. The results showed that activation corresponding to ground regions was reduced for high-vs. low-competition silhouettes in V4, where receptive fields (RFs) are large enough to encompass the familiar objects in the grounds, and in V1/V2, where RFs are much smaller. These results support a theory of object perception involving competitionmediated ground suppression and feedback from higher to lower levels. This pattern of results was observed in the left hemisphere (RVF), but not in the right hemisphere (LVF). One explanation of the lateralized findings is that task-irrelevant silhouettes in the RVF captured attention, allowing us to observe these effects, whereas those in the LVF did not. Experiment 2 provided preliminary behavioral evidence consistent with this possibility.

show abstract

Section: Discussionmentioning

confidence: 99%

Neural evidence for competition-mediated suppression in the perception of a single object

Cacciamani

Scalf

Peterson

2015

Cortex

View full text Add to dashboard Cite

show abstract

“…This is summarised nicely by Lee and Mumford (2003); "Recent electrophysiological recordings from early visual neurons in awake behaving monkeys reveal that there are many levels of complexity in the information processing of the early visual cortex, as seen in the long latency responses of its neurons. These new findings suggest that activity in the early visual cortex is tightly coupled and highly interactive with the rest of the visual system".…”

Section: Long-latency Evoked Responsesmentioning

confidence: 99%

Free-energy and the brain

2007

View full text Add to dashboard Cite

If one formulates Helmholtz's ideas about perception in terms of modern-day theories one arrives at a model of perceptual inference and learning that can explain a remarkable range of neurobiological facts. Using constructs from statistical physics it can be shown that the problems of inferring what cause our sensory inputs and learning causal regularities in the sensorium can be resolved using exactly the same principles. Furthermore, inference and learning can proceed in a biologically plausible fashion. The ensuing scheme rests on Empirical Bayes and hierarchical models of how sensory information is generated. The use of hierarchical models enables the brain to construct prior expectations in a dynamic and context-sensitive fashion. This scheme provides a principled way to understand many aspects of the brain's organisation and responses. In this paper, we suggest that these perceptual processes are just one emergent property of systems that conform to a free-energy principle. The free-energy considered here represents a bound on the surprise inherent in any exchange with the environment, under expectations encoded by its state or configuration. A system can minimise free-energy by changing its configuration to change the way it samples the environment, or to change its expectations. These changes correspond to action and perception, respectively, and lead to an adaptive exchange with the environment that is characteristic of biological systems. This treatment implies that the system's state and structure encode an implicit and probabilistic model of the environment. We will look at models entailed by the brain and how minimisation of free-energy can explain its dynamics and structure.

show abstract

“…The issues considered here are very general ones, and have a long history in our field. There are general theories in which top-down influences affect all levels of language processing [5], and similar proposals have been offered for the role of top-down or contextual influences in vision [6] and motor action selection [7]. Again this approach contrasts with other proposals, such as those of Marr [8] and Fodor [9], in which separate and impenetrable modules carry out automatic perceptual and motor processes.…”

Section: Introductionmentioning

confidence: 99%

Are there interactive processes in speech perception?

McClelland

Mirman

Holt

2006

Trends in Cognitive Sciences

231

191

View full text Add to dashboard Cite

Lexical information facilitates speech perception, especially when sounds are ambiguous or degraded. The interactive approach to understanding this effect posits that this facilitation is accomplished through bi-directional flow of information, allowing lexical knowledge to influence pre-lexical processes. Alternative autonomous theories posit feed-forward processing with lexical influence restricted to post-perceptual decision processes. We review evidence supporting the prediction of interactive models that lexical influences can affect pre-lexical mechanisms, triggering compensation, adaptation and retuning of phonological processes generally taken to be pre-lexical. We argue that these and other findings point to interactive processing as a fundamental principle for perception of speech and other modalities.

show abstract

Hierarchical Bayesian inference in the visual cortex

Cited by 1,265 publications

References 58 publications

Neural evidence for competition-mediated suppression in the perception of a single object

Neural evidence for competition-mediated suppression in the perception of a single object

Free-energy and the brain

Are there interactive processes in speech perception?

Contact Info

Product

Resources

About