Cited by 2,476Neural dynamics and brain functionEmbodied and Extended CognitionVisual perception and processing mechanisms

Canonical Microcircuits for Predictive Coding

Open access
Bastos, Andre M., Usrey, W. Martin, Adams, Rick A., Mangun, George R., Fries, Pascal, Friston, Karl J.·2012·Neuron

Abstract

This Perspective considers the influential notion of a canonical (cortical) microcircuit in light of recent theories about neuronal processing. Specifically, we conciliate quantitative studies of microcircuitry and the functional logic of neuronal computations. We revisit the established idea that message passing among hierarchical cortical areas implements a form of Bayesian inference-paying careful attention to the implications for intrinsic connections among neuronal populations. By deriving canonical forms for these computations, one can associate specific neuronal populations with specific computational roles. This analysis discloses a remarkable correspondence between the microcircuitry of the cortical column and the connectivity implied by predictive coding. Furthermore, it provides some intuitive insights into the functional asymmetries between feedforward and feedback connections and the characteristic frequencies over which they operate.

Integrity signals

Registry

Crossref · 10.1016/j.neuron.2012.10.038

Cites

160 of 160 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

36 of 125 cited sources checked · 23 supported · 1 flagged · accuracy not yet measured

  • Premisecitation

    In predictive coding, attention is mediated by increasing the gain of populations encoding prediction error.

    “in predictive coding, attention is mediated by increasing the gain of populations encoding prediction error (Spratling, 2008; Feldman and Friston, 2010).”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites Spratling, 2008 source

      In RECONCILING PREDICTIONS (page unavailable), Spratling says that top-down predictions suppress error-detecting neurons while enhancing a subset of prediction neurons. The paper locates attention-related enhancement in the prediction nodes, not in increased gain of populations encoding prediction error. (LLM, conf=0.86)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites Feldman and Friston, 2010 source
    • Rests on an assumption: In predictive coding, feedforward connections carry prediction errors and feedback connections carry predictions that suppress lower-level prediction errors.
  • Premisecitation

    In mouse V1/V2 and A1/A2, stimulating feedforward or feedback afferents produced both driving-like and modulatory-like responses.

    “In both cases, driving-like responses as well as modulatory-like responses were observed (Covic and Sherman, 2011; De Pasquale and Sherman, 2011).”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites Covic and Sherman, 2011 source
    • cites De Pasquale and Sherman, 2011 source
  • Premisecitation

    About 95% of neurons labelled by a retrograde tracer lie within roughly 2 mm of the injection site, indicating intrinsic connections dominate by number.

    “By numbers alone, intrinsic connections appear to dominate – 95% of all neurons labelled with a retrograde tracer lie within about 2 mm of the injection site (Markov et al., 2011).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Markov et al., 2011 source

      The Results (FLN Values: Local, Long Distance, and Subcortical) say that 95% of *intrinsic* labeled neurons were within 1.9 mm of the injection site, not 95% of all labeled neurons. The same section reports that intrinsic neurons accounted for a mean of 79% of labeled neurons, supporting the conclusion that intrinsic connections dominate by number but not the claim's 95% figure for all neurons. (LLM, conf=0.92)

      Experimental — accuracy not yet measured
  • Interpretationcitation

    The suppression of responses to predictable stimuli cannot be explained by local adaptation because the predictable attributes are not represented in early sensory cortex.

    “Crucially, this suppression cannot be explained in terms of local adaptation, because the attributes of the stimuli that can be predicted are not represented in early sensory cortex (e.g., Harrison et al. 2007).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Harrison et al. 2007 source
  • Premisecitation

    Electrophysiological mismatch negativity studies suggest that neural responses to deviant stimuli that violate sensory predictions are enhanced relative to predicted stimuli.

    “For example, electrophysiological studies of the mismatch negativity suggest that neural responses to deviant stimuli – that violate sensory predictions established by a regular stimulus sequence – are enhanced relative to predicted stimuli (Garrido et al., 2009).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Garrido et al., 2009 source
  • May combine two claims. 47
  • Classified as probably not a substantial claim. 14
  • The quote only partly states this claim. 2
  • May combine two claims.

    Premisecitation

    Superficial cortical layers show neuronal synchronization and spike-field coherence mainly at gamma frequencies, whereas deep layers prefer lower alpha or beta frequencies.

    “recent findings suggest that the superficial layers of cortex show neuronal synchronization and spike-field coherence predominantly in the gamma frequencies, while deep layers prefer lower (alpha or beta) frequencies (Roopun et al., 2006, 2008; Maier et al., 2010; Buffalo et al., 2011).”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites Roopun et al., 2006, 2008

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Maier et al., 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Buffalo et al., 2011 source
  • May combine two claims.

    Premisecitation

    Optogenetic driving of L6 principal cells in V1 inhibited their extrinsic targets in LGN and intrinsic targets in cortical layers 2 to 5.

    “the authors showed that deep L6 principal cells inhibited their extrinsic targets in the LGN and their intrinsic targets in cortical layers 2 to 5 (Olsen et al., 2012).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Olsen et al., 2012 source
  • May combine two claims.

    Premisecitation

    The LGN-to-V1 connection is only the sixth strongest input to V1 but has a substantial effect on V1 responses.

    “A case in point is the LGN to V1 connection: although it is only the sixth strongest connection to V1, LGN afferents have a substantial effect on V1 responses (Markov et al., 2011).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Markov et al., 2011 source

      The Results (Interareal Connectivity Profiles; page unavailable) describe a small LGN input to V1, and the Discussion (Connectivity Profiles: Local Versus Long Distance, and Subcortical; page unavailable) reports an LGN-to-V1 FLNt of 0.16% and discusses amplification of sparse thalamic signals by local circuits. Our copy does not establish that LGN is specifically the sixth strongest input or directly measure its effect on V1 responses. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    In Olsen et al., LGN visual responses were suppressed by 76%, and V1 suppression was around 80-84%.

    “This suppression was powerful – in the LGN, visual responses were suppressed by 76%. Suppression was also high in V1, around 80-84% (Olsen et al., 2012).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Olsen et al., 2012 source
  • May combine two claims.

    Premisecitation

    Sherman and Guillery identified properties distinguishing driving from modulatory connections: driving connections have strong ionotropic components, large EPSPs, and depressing responses to multiple EPSPs; modulatory connections have metabotropic and ionotropic responses, weak EPSPs, and paired-pulse facilitation.

    “Driving connections tend to show a strong ionotropic component in their synaptic response, evoke large EPSPs, and respond to multiple EPSPs with depressing synaptic effects. Modulatory connections produce metabotropic and ionotropic responses when stimulated, evoke weak EPSPs, and show paired-pulse facilitation (Sherman and Guillery, 1998; 2011).”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Sherman and Guillery, 1998 source

      Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

      Experimental — accuracy not yet measured
    • cites Sherman and Guillery, 2011 source
  • May combine two claims.

    Premisecitation

    The remaining 5% of labelled cells give rise to extrinsic connections, which are sparse but can be very effective in driving targets.

    “The remaining 5% represent cells giving rise to extrinsic connections, which – although sparse – can be extremely effective in driving their targets.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Markov et al., 2011 source

      The Results section (FLN Values: Local, Long Distance, and Subcortical; page unavailable) assigns about 5% of labeled neurons to long-range corticocortical connections, but also reports about 16% from adjoining cortical areas; 5% is therefore not the total for extrinsic connections. The Discussion (Connectivity Profiles: Local Versus Long Distance, and Subcortical; page unavailable) says weak cortical inputs can be robust and reliable and may transmit effectively, but does not establish that these connections are extremely effective at driving their targets. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    In mouse barrel cortex, the strongest connections are intralaminar, and the strongest interlaminar connections are ascending L4 to L2 and descending L3 to L5.

    “As in visual cortex, the strongest connections were intralaminar and the strongest interlaminar connections were the ascending L4 to L2, and descending L3 to L5.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Lefort et al., 2009 source
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Feedforward connections are traditionally viewed as strong and driving, able to elicit spiking and confer classical receptive field properties, while feedback connections are thought to modulate extra-classical receptive field properties according to context.

    “The traditional view holds that feedforward connections are strong and driving, capable of eliciting spiking activity in their targets and conferring classical receptive field properties – the prototypical example being the synaptic connection between LGN and V1 (Sherman and Guillery, 1998). Feedback connections are thought to modulate (extra-classical) receptive field characteristics according to”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Sherman and Guillery, 1998 source

      Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    Layer 1 cells are almost all inhibitory and interconnect strongly via electrical connections and chemical synapses.

    “These L1 cells are almost all inhibitory and interconnect strongly with each other, via electrical connections and chemical synapses (Chu et al., 2003).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Chu et al., 2003 source

      The Abstract says histochemical studies suggest most layer 1 neurons are GABAergic, but it does not establish that almost all are inhibitory. The ‘Electrical coupling and inhibitory connections among LS cells’ section reports electrical coupling in 83% and chemical connections in 26.2% of tested late-spiking cell pairs. Those findings support interconnection within that cell class, not a strong interconnection among layer 1 cells generally. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The thalamic reticular nucleus has been proposed to mediate inhibition underlying cross-modal attention or top-down predictions.

    “In addition, the thalamic reticular nucleus has been proposed to mediate the inhibition that might underlie cross-modal attention or top-down predictions (Yamaguchi and Knight, 1990; Crick, 1984; Wurtz et al., 2011).”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites Yamaguchi and Knight, 1990 source
    • cites Crick, 1984 source
    • cites Wurtz et al., 2011 source

      In “Modulation of Thalamic Reticular and Lateral Geniculate Neurons by Attention” (page unavailable), the paper describes inhibitory projections from the thalamic reticular nucleus and a proposed role in visual attention. It does not connect that inhibition to cross-modal attention or top-down predictions; its discussion of the attentional mechanism is limited to visual spatial attention. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    In visual cortex, superficial-layer neuron spiking is more coherent with gamma LFP oscillations, while deep-layer neuron spiking is more coherent with alpha oscillations.

    “the spiking activity of neurons in the superficial layers of visual cortex are more coherent with gamma frequency oscillations in the local field potential, while neurons in deep layers are more coherent with alpha frequency oscillations (Buffalo et al., 2011).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Buffalo et al., 2011 source
  • May combine two claims.

    Premisecitation

    The corticogeniculate feedback pathway from L6 preserves stream segregation: upper L6 cells preferentially synapse onto parvocellular LGN cells, and lower L6 cells target magnocellular LGN layers.

    “The corticogeniculate feedback pathway from L6 maintains this segregation, as upper L6 cells preferentially synapse onto parvocellular cells in the LGN, while lower L6 cells target the magnocellular LGN layers (Fitzpatrick et al., 1994; Briggs and Usrey, 2009).”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites Fitzpatrick et al., 1994 source
    • cites Briggs and Usrey, 2009 source
  • May combine two claims.

    Interpretationcitation

    Feedback connections could arise directly from cells encoding conditional expectations in supragranular layers, and emerging evidence indicates that feedback connections between proximate hierarchical levels originate from both deep and superficial layers.

    “For example, feedback connections could arise directly from cells encoding conditional expectations in supragranular layers. Indeed, there is emerging evidence that feedback connections between proximate hierarchical levels originate from both deep and superficial layers (Markov et al 2011).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Markov et al 2011 source

      Split into 2 atoms — 0 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 2 unverifiable. Expand the claim to see per-atom verdicts.

      Experimental — accuracy not yet measured
  • May combine two claims.

    Interpretationcitation

    The contribution of any angular frequency in prediction errors to expectations is suppressed in proportion to that frequency, so high frequencies are attenuated when passing from superficial to deep pyramidal cells.

    “This equation says that the contribution of any (angular) frequency ω in the prediction errors (encoded by superficial pyramidal cells) to the expectations (encoded by the deep pyramidal cells) is suppressed in proportion to that frequency (Friston 2008). In other words, high frequencies should be attenuated when passing from superficial to deep pyramidal cells.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Friston 2008 source

      The Results section (Neuronal Implementation; page unavailable) identifies superficial pyramidal cells with prediction errors and deep pyramidal cells with expected causes. Its Summary says cells elaborating predictions may have low-pass dynamics relative to error-encoding cells, supporting high-frequency attenuation as a possibility. Our copy does not state that each frequency’s contribution is suppressed in proportion to its angular frequency. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S2 (checkable).

    Premisecitation

    Predictive coding is arguably the most plausible neurobiological candidate for making these inferences.

    “In terms of implementation, predictive coding is, arguably, the most plausible neurobiological candidate for making these inferences (Srinivasan et al., 1982; Mumford, 1992; Rao and Ballard, 1999).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Srinivasan et al., 1982 source
    • cites Mumford, 1992 source
    • cites Rao and Ballard, 1999 source
  • May combine two claims.

    Premisecitation

    Feedforward connections originate predominantly from superficial layers and feedback connections from deep layers.

    “Since feedforward connections originate predominately from superficial layers and feedback connections from deep layers”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Felleman and Van Essen, 1991 source
  • May combine two claims.

    Premisecitation

    In Douglas and Martin's model, superficial and deep pyramidal cells plus a common inhibitory pool all received thalamic drive and were fully interconnected.

    “Their model contained superficial and deep pyramidal cells with a common pool of inhibitory cells. All three neuronal populations received thalamic drive and were fully interconnected.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Douglas and Martin, 1991 source
  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Such output segregation can only arise from local neuronal computations that are structured and precisely interconnected.

    “This segregation can only arise from local neuronal computations that are structured and precisely interconnected.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Premisecitation

    The brain uses internal or generative models to infer the causes of sensory input.

    “This notion builds on a long history of proposals that the brain uses internal or generative models to make inferences about the causes of its sensorium (Helmholtz, 1860; Gregory 1968, 1980; Dayan et al., 1995).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Helmholtz, 1860

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Gregory 1968, 1980

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Dayan et al., 1995 source
  • Classified as probably not a substantial claim.

    Premisecitation

    The brain actively constructs explanations for its sensory inputs.

    “The idea that the brain actively constructs explanations for its sensory inputs is now generally accepted.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Helmholtz, 1860

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Gregory 1968, 1980

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Dayan et al., 1995 source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The Douglas-Martin circuit was proposed as a basic motif that might be replicated with minor variations across the cortical sheet.

    “Their circuit, although based on recordings from cat visual cortex, was also proposed as a basic theme that might be present and replicated, with minor variations, throughout the cortical sheet (Douglas et al., 1989).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Douglas et al., 1989 source
  • The quote only partly states this claim.

    Premisecitation

    In mouse M1, S1, and V1, L4 inhibitory connections have a more restricted lateral extent than those in other layers.

    “first, L4 inhibitory connections are more restricted in their lateral extent, relative to other layers.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Kätzel et al., 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Cortical feedback contributes to surround suppression of feline LGN cells; without feedback, LGN cells are disinhibited and show weaker surround suppression.

    “This evidence is in line with classical studies of corticogeniculate contributions to length tuning in the LGN, showing that cortical feedback contributes to the surround suppression of feline LGN cells: without feedback, LGN cells are disinhibited and show weaker surround suppression (Murphy and Sillito, 1987; Sillito et al., 1993; but see Alitto and Usrey, 2008).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Murphy and Sillito, 1987 source
    • cites Sillito et al., 1993 source
    • cites Alitto and Usrey, 2008 source
  • May combine two claims.

    Premisecitation

    Feedforward connections originate largely from superficial pyramidal cells and target L4, while feedback connections originate largely from deep pyramidal cells and terminate outside L4.

    “Feedforward connections originate largely from superficial pyramidal cells and target L4, while feedback connections originate largely from deep pyramidal cells and terminate outside of L4 (Felleman and van Essen 1991).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Felleman and van Essen 1991 source
  • May combine two claims.

    Premisenone given

    Normal subjects rapidly adapt to deviant stimuli as they become predictable, an effect not seen in prefrontal patients.

    “Furthermore, normal subjects show a rapid adaptation to deviant stimuli as they become predictable – an effect not seen in prefrontal patients.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning

    Predictive coding requires feedback connections to drive lower-level cells in a context-sensitive way, which necessitates a modulatory component in their postsynaptic effects.

    “In short, predictive coding requires feedback connections to drive cells in lower levels in a context sensitive fashion, which necessitates a modulatory aspect to their postsynaptic effects.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: In predictive coding, feedforward connections carry prediction errors and feedback connections carry predictions that suppress lower-level prediction errors.
    • Rests on an assumption: Top-down predictions are context sensitive.
  • May combine two claims.

    Premisecitation

    In cat and rat visual cortex, the most frequently connected cells are in the same layer, and the largest interlaminar projections are feedforward from L4 to L3 and L3 to L5.

    “The most frequently connected cells were located in the same cortical layer, where the largest interlaminar projections were the ‘feedforward’ connections from L4 to L3 and from L3 to L5.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Thomson et al 2002 source
  • May combine two claims.

    Premisecitation

    Patients with prefrontal damage show reduced-amplitude P300 ERPs to novel stimuli, as if top-down predictions fail to reach sensory cortex.

    “In contrast, they show reduced-amplitude P300 ERPs in response to novel stimuli – as if there were a failure to communicate top-down predictions to sensory cortex (Knight, 1984).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Knight, 1984 source
  • May combine two claims.

    Premisecitation

    Excitatory reciprocal feedback connections were absent from L3 to L4 or less common from L5 to L3, suggesting excitation spreads within the column in a feedforward manner.

    “Excitatory reciprocal ‘feedback’ connections were not observed (L3 to L4) or less commonly observed (L5 to L3), suggesting that excitation spreads within the column in a feedforward fashion.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Thomson et al 2002 source
  • May combine two claims.

    Premisecitation

    In granular cortex, several interlaminar inhibitory motifs appear general, especially strong inhibition from L4 onto supragranular L2/3 and from infragranular layers onto L4.

    “Third, several interlaminar motifs appeared to be general – at least in granular cortex: principally, a strong inhibitory connection from L4 onto supragranular L2/3 and from infragranular layers onto L4.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Kätzel et al., 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    The largest fraction of synaptic input in mouse motor cortex arrives in L5A/B, consistent with a key role in accumulating information from diverse afferents before corticospinal output.

    “The largest fraction of synaptic input arrived in L5A/B, consistent with its key role in accumulating information from a wide range of afferents – before sending its output to the corticospinal tract.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Weiler et al., 2008 source
  • Classified as probably not a substantial claim.

    Premisecitation

    The cortex is hierarchically organized.

    “Current dogma holds that the cortex is hierarchically organized.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Felleman and Van Essen, 1991 source
  • Classified as probably not a substantial claim.

    Premisecitation

    Extrinsic cortical connections are classified as feedforward, feedback, or lateral, distinguished by laminar origins and targets.

    “The idea of a cortical hierarchy rests on the distinction between three types of extrinsic connections: feedforward connections, that link an earlier area to a higher area, feedback connections, that link a higher to an earlier area, and lateral connections, that link areas at the same level (reviewed in Felleman and Van Essen, 1991).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Felleman and Van Essen, 1991 source
  • May combine two claims.

    Premisenone given

    In primates, parvocellular input enters cortex mainly in layer 4Cβ, while magnocellular input enters mainly in layer 4Cα.

    “in primates, parvocellular input enters the cortex primarily in layer 4Cβ, whereas magnocellular inputs enter in 4Cα.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Premisecitation

    In rat somatomotor cortex, L2/3 shows prominent gamma oscillations co-expressed with beta oscillations in L5, and both rhythms persist when superficial and deep layers are disconnected at L4.

    “Roopun et al. (2006) showed that L2/3 of rat somatomotor cortex shows prominent gamma oscillations that are co-expressed with beta oscillations in L5. Both rhythms persisted, when superficial and deep layers were disconnected at the level of L4.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Roopun et al. (2006) source
  • May combine two claims.

    Premisereasoning

    Because entropy is the average surprise over time, biological systems minimise the surprise associated with their sensory states at each moment.

    “Entropy is the average of surprise over time, which means biological systems minimise the surprise associated with their sensory states at each point in time.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Friston, 2010 source
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Extrinsic corticocortical connections are established as exclusively excitatory, although recent evidence suggests inhibitory extrinsic connections exist and may synchronize distant regions.

    “The established view is that extrinsic corticocortical connections are exclusively excitatory (using glutamate as their excitatory neurotransmitter) – although recent evidence suggests that inhibitory extrinsic connections exist and may play an important role in synchronizing distant regions (Melzer et al., 2012).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Melzer et al., 2012 source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cortical columns with structured connectivity are computationally more efficient than networks with the same number of neurons but random connectivity.

    “Computational modelling studies indicate that cortical columns with structured connectivity are computationally more efficient than a network containing the same number of neurons but with random connectivity (Haeusler and Maass, 2007).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Haeusler and Maass, 2007 source
  • May combine two claims.

    Premisecitation

    Supragranular sites have higher broadband gamma power than infragranular sites, whereas alpha and beta power is greater in infragranular and granular layers.

    “Maier et al., found that supragranular sites had higher broadband gamma power than infragranular sites. This pattern was reversed in the alpha and beta range; with greater power in the infragranular and granular layers.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Maier et al. (2010)

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationcitation

    Although superficial and deep cortical layers are anatomically interconnected, they form functionally distinct processing streams.

    “Superficial and deep layers are anatomically interconnected, but mounting evidence suggests that they constitute functionally distinct processing streams”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Roopun et al. (2006) source
    • cites Maier et al. (2010)

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    When stimuli spanned the extra-classical receptive field, cooling V5/MT enhanced V1 responses on average, consistent with a suppressive role of feedback.

    “However, when the authors used a stimulus that spanned the extra-classical RF the responses of V1 neurons were – on average – enhanced after cooling area V5, consistent with the suppressive role of feedback connections.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Hupé et al., 1998 source
  • May combine two claims.

    Premisecitation

    Multilaminar recordings show strong LFP coherence among sites within superficial layers and within deep layers, but weak coherence between the two compartments.

    “Maier and colleagues (2010) used multilaminar recordings to show strong LFP coherence amongst sites within the superficial layers (the superficial compartment), as well as strong coherence amongst sites in deep layers (the deep compartment), but weak inter-compartment coherence.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Maier et al. (2010)

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Rao and Ballard trained a hierarchical predictive coding network on natural images and showed that higher levels learn to predict visual features extending across many lower-level CRFs.

    “Rao and Ballard (1999) trained a hierarchical predictive coding network to recognise natural images. They showed that higher levels in the hierarchy learn to predict visual features that extend across many CRFs in the lower levels (e.g. tree trunks or horizons).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Rao and Ballard (1999) source
  • May combine two claims.

    Premisecitation

    When V2 was cooled and V1 neurons recorded, cooling decreased V1 spiking for CRF-only stimuli but increased V1 activity when stimuli were in both CRF and surround.

    “Similar effects were observed when area V2 was cooled and neurons were measured in V1: when stimuli were presented only to the CRF, cooling V2 decreased V1 spiking activity; however, when stimuli were present in the CRF and the surround, cooling V2 increased V1 activity (Bullier et al., 1996).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Bullier et al., 1996 source
  • May combine two claims.

    Premisecitation

    In macaque V1, a significant proportion of superficial L2/3 cells (about half) and deep L5 excitatory cells (about 80%) do not project outside the cortical column.

    “This accommodates the fact that (in macaque V1) a significant percentage of superficial L2/3 cells (about half) and deep L5 excitatory cells (about 80%) do not project outside the cortical column (Callaway and Wiser, 1996; Briggs and Callaway, 2005).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Callaway and Wiser, 1996 source
    • cites Briggs and Callaway, 2005 source
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    There are many variations on the mapping between computational and neuronal architectures; even if predictive coding is an appropriate implementation of Bayesian filtering, the arrangement in Figure 5 is only one of several possibilities.

    “Having said this, there are many variations on the mapping between computational and neuronal architectures: Even if predictive coding is an appropriate implementation of Bayesian filtering, there are many variations on the arrangement shown in Figure 5.”
    Quote in the paperNot a substantial claim
  • May combine two claims. The quote only partly states this claim.

    Interpretationreasoning

    The circuitry in Figure 5 is consistent with the broad scheme of ascending feedforward and descending feedback intrinsic connections and recapitulates the functional asymmetries between extrinsic feedforward and feedback connections.

    “The circuitry in Figure 5 appears consistent with the broad scheme of ascending (feedforward) and descending (feedback) intrinsic connections: feedforward prediction errors from a lower cortical level arrive at granular layers and are passed forward to excitatory and inhibitory interneurons in supragranular layers, encoding expectations.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    Excitatory and inhibitory interneurons in the supragranular layer are assigned expectations about hidden causes and hidden states, respectively.

    “The remaining populations are the excitatory and inhibitory interneurons in the supragranular layer, to which we assign expectations about hidden causes and states respectively.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning

    The arrangement accommodates the fact that dependencies among hidden states are confined to each node, so their expectations and prediction errors should be encoded by interneurons; splitting upper-layer excitatory cells into two populations is sensible because there is a one-to-one mapping between expectations on hidden causes and their prediction errors.

    “This arrangement accommodates the fact that the dependencies among hidden states are confined to each node (by the nature of graphical models), which means that their expectations and prediction errors should be encoded by interneurons. Furthermore, the splitting of excitatory cells in the upper layers into two populations (encoding expectations and prediction errors on hidden causes) is sensible,”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning

    Predictions are formed by a linear accumulation of prediction errors, while prediction errors are nonlinear functions of predictions.

    “In summary, predictions are formed by a linear accumulation of prediction errors. Conversely, prediction errors are nonlinear functions of predictions.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning

    Superficial pyramidal cells must encode and broadcast prediction errors on hidden causes, while deep pyramidal cells must encode conditional expectations so they can elaborate feedback predictions.

    “This means that superficial pyramidal cells must encode and broadcast prediction errors on hidden causes ξv(i+1), while deep pyramidal cells must encode conditional expectations (μ~v(i),μ~x(i)) so that they can elaborate feedback predictions.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Superficial pyramidal cells provide feedforward connections, while deep pyramidal cells provide feedback connections.
  • May combine two claims.

    Interpretationreasoning

    This smoothing leads to an asymmetry in frequency content: superficial cells should express more gamma relative to beta, and deep cells should express more beta relative to gamma.

    “This smoothing – inherent in Bayesian filtering – leads to an asymmetry in frequency content of superficial and deep cells: for example, superficial cells should express more gamma relative to beta, and deep cells should express more beta relative to gamma (Roopun et al., 2006, 2008; Maier et al., 2010).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Roopun et al., 2006, 2008

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Maier et al., 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    Converting prediction errors into predictions necessarily entails a loss of high frequencies, but the nonlinearity in the mapping from predictions to prediction errors means high frequencies can be created.

    “This means that the conversion of prediction errors into predictions (Bayesian filtering) necessarily entails a loss of high frequencies. However, the nonlinearity in the mapping from predictions to prediction errors means that high frequencies can be created (consider the effect of squaring a sine wave, which would convert beta into gamma).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Inhibitory interneurons in the granular layer are associated with prediction errors on hidden states.

    “This leaves the inhibitory interneurons in the granular layer, which, for symmetry, we associate with prediction errors on the hidden states.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning

    There is a remarkable correspondence between the form of Equation (1) and the connectivity of the canonical microcircuit, and the resulting scheme corresponds almost exactly to the computational architecture proposed by Mumford (1992).

    “Figure 5 illustrates a remarkable correspondence between the form of Equation (1) and the connectivity of the canonical microcircuit. Furthermore, the resulting scheme corresponds almost exactly to the computational architecture proposed by Mumford (1992).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Mumford (1992) source
    • Rests on an assumption: A cortical column contains the circuitry needed for the relevant computations, and this circuitry is replicated with only minor variations across cortex.
  • May combine two claims.

    Interpretationreasoning

    Top-down predictions produce prediction errors through subtraction, so feedback connections should exert inhibitory effects, as observed empirically.

    “Another key feature of Equation (1) is that the top-down predictions produce prediction errors through subtraction. In other words, feedback connections should exert inhibitory effects, of the sort seen empirically.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning

    By minimising surprise through selecting appropriate sensations, the brain implicitly maximises the evidence for its own existence, a process known as active inference.

    “These arguments mean that by minimising surprise, through selecting appropriate sensations, the brain is implicitly maximising the evidence for its own existence – this is known as active inference.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning

    There are two exceptions involving connections to inhibitory cells in the granular layer; predictive coding requires interlaminar projections from supragranular inhibitory and infragranular excitatory cells, which should be of a feedback sort.

    “However, there are two exceptions that both involve connections to the inhibitory cells in the granular layer (shown as dotted lines in Figure 5). Predictive coding requires that these cells (that encode prediction errors on hidden states) compare the expected changes in hidden states with the actual changes. This suggests that there should be interlaminar projections from supragranular (inhibitor”
    Quote in the paperSubstantial claim
58 of 58
  • The paper relies on this without support.

    In predictive coding, feedforward connections carry prediction errors and feedback connections carry predictions that suppress lower-level prediction errors.

    “In predictive coding, feedforward connections convey prediction errors, while feedback connections convey predictions from higher cortical areas to suppress prediction errors in lower areas.”
  • The paper relies on this without support.

    Top-down predictions are context sensitive.

    “This is because top-down predictions are necessarily context sensitive: e.g., the occlusion of one visual object by another.”
  • The authors state this as an assumption.

    Each canonical microcircuit is distinct from its neighbours and can carry out computations in parallel.

    “The notion of a canonical microcircuit implicitly assumes that each circuit is distinct from its neighbours; that could presumably carry out computations in parallel.”
  • The paper relies on this without support.

    A cortical column contains the circuitry needed for the relevant computations, and this circuitry is replicated with only minor variations across cortex.

    “Central to the idea of a canonical microcircuit is the notion that a cortical column contains the circuitry necessary to perform requisite computations, and that these circuits can be replicated with minor variations throughout the cortex.”
  • The paper relies on this without support.

    Superficial pyramidal cells provide feedforward connections, while deep pyramidal cells provide feedback connections.

    “Second, we know that the superficial and deep pyramidal cells provide feedforward and feedback connections respectively.”
5 of 5

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Descending activity, carried by alpha/beta-band activity, is strongest in layers 5/6.

    “Consistent with the proposed laminar profile of PP dynamics, evidence from monkey and human studies indicate that gamma‐band activity predominantly emanates from forward projections in superficial layers, while descending activity, carried by alpha/beta‐band activity, is strongest in layers 5/6.”

    From Evaluating the neurophysiological evidence for predictive processing as a model of perception (2020) · cites this paper as [40]

    The Introduction says deep layers prefer alpha/beta frequencies and that feedback connections originate predominantly there. In “Segregation of processing streams,” however, the paper calls low-frequency feedback signalling a proposal and says experimental support was available at least for feedforward connections. It therefore does not establish as firmly as the claim suggests that descending activity is carried by alpha/beta activity or is strongest specifically in layers 5/6. (LLM, conf=0.83)

    Experimental — accuracy not yet measured
  • Evidence from monkey and human studies indicates that gamma-band activity predominantly emanates from forward projections in superficial layers.

    “Consistent with the proposed laminar profile of PP dynamics, evidence from monkey and human studies indicate that gamma‐band activity predominantly emanates from forward projections in superficial layers, while descending activity, carried by alpha/beta‐band activity, is strongest in layers 5/6.”

    From Evaluating the neurophysiological evidence for predictive processing as a model of perception (2020) · cites this paper as [40]

    The Introduction and “Segregation of processing streams” report predominant gamma activity in superficial layers, where feedforward connections originate, and cite experimental support for higher-frequency feedforward signaling. The passages describe monkey findings but do not establish that the claimed laminar and feedforward pattern was also shown in human studies. (LLM, conf=0.82)

    Experimental — accuracy not yet measured
  • Accumulating evidence suggests a role for superficial pyramidal cells in representation (prediction) and error coding, while L5 cells may function especially in representation coding.

    “Accumulating evidence suggests a role for superficial pyramidal cells in representation (prediction) and error coding, while L5 cells may function especially in representation coding.23,118,135”

    From An integrative, multiscale view on neural theories of consciousness (2024) · cites this paper as [23]

    In “The cortical microcircuit and predictive coding” (page unavailable), the paper assigns prediction-error coding to superficial pyramidal cells and conditional-expectation coding to deep pyramidal cells, consistent with the claim about L5 representation coding. It assigns expectation coding in superficial layers to excitatory interneurons, not superficial pyramidal cells, so the claimed dual role for superficial pyramidal cells is not supported. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • PP-based accounts, including NREP, propose that conscious vision begins with the interaction between the feedforward signaling stream (mainly conveying error information) and the recurrent stream (conveying top-down predictions) within the visual cortical hierarchy, although alternative schemes are possible.

    “PP-based accounts, including NREP, propose that conscious vision begins with the interaction between the feedforward signaling stream (mainly conveying error information) and the recurrent stream (conveying top-down predictions) within the visual cortical hierarchy, 23,141,135 although alternative schemes are possible (e.g., Heeger 162 ).”

    From An integrative, multiscale view on neural theories of consciousness (2024) · cites this paper as [23]

    Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured
  • Predictions and incoming sensory input each have an associated precision (inverse variance) reflecting their confidence or reliability.

    “According to these theories, predictions and incoming sensory input each have an associated precision (inverse variance) reflecting their confidence or reliability.”

    From Precision weighting of cortical unsigned prediction error signals benefits learning, is mediated by dopamine, and is impaired in psychosis (2021) · cites this paper as [6]

    In “Predictive coding and message passing” (page unavailable), the paper says prediction errors are weighted by precision, defined as inverse variance, when top-down predictions are compared with sensory input. It does not explicitly assign a separate precision to each prediction and each incoming sensory input, or define those precisions as their respective confidence or reliability. (LLM, conf=0.82)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Stated column widths do not span three orders of magnitude

    Minor

    The stated widths run from roughly 50 micrometers for minicolumns to 1 mm (1,000 micrometers) for hypercolumns-a factor of about 20, not 1,000.

1 of 1

Cites

Flagged first, then by citations

6 of the 166 references couldn’t be matched to a known paper.

Cited by

Sorted by citations

Authors
Bastos, A. M., Usrey, W. M., Adams, R. A., Mangun, G. R., Fries, P., & Friston, K. J.
Affiliations
  • University of California, Davis (US)
  • Wellcome Centre for Human Neuroimaging (GB)
  • Radboud University Nijmegen (NL)
Corresponding author
Friston, Karl J.
Venue
Neuron
Publisher
Elsevier BV
Published
2012-11
Volume
76
Issue
4
Pages
695-711
ISSN
0896-6273 (ISSN-L)
OpenAlex
W2120079537
Cited by
2,421
References
166
Citations by year
2026: 222 · 2025: 233 · 2024: 199 · 2023: 238 · 2022: 186 · 2021: 217 · 2020: 235 · 2019: 175 · 2018: 165 · 2017: 147 · 2016: 117 · 2015: 114 · 2014: 121 · 2013: 48 · 2012: 3
FWCI
7.25
Type
journal article
Language
en
Open access
Locations
  • Neuron (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
  • Max Planck Institute for Plasma Physics (submittedVersion)
  • UCL Discovery (University College London) (submittedVersion)
  • University of Birmingham Research Portal (University of Birmingham) (submittedVersion, other-oa)
  • MPG.PuRe (Max Planck Society) (submittedVersion)
  • Radboud Repository (Radboud University) (submittedVersion)
Funders
  • National Institutes of Health (1228535, EY013588, MH055714)
  • Wellcome Trust
  • National Science Foundation (2009090358)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Neural dynamics and brain function
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Embodied and Extended Cognition
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Visual perception and processing mechanisms
Keywords
predictive coding, cortical microcircuitry, Bayesian inference, intrinsic connections, cortical columns, cortical connectivity
MeSH terms
Animals, Cerebral Cortex, Computer Simulation, Humans, Functional Laterality, Models, Neurological, Nerve Net, Neural Pathways, Feedback, Physiological

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read under definition version 3 (extract-v3) on 2026-09-28.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-09-28.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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