Source
- Block (2019), What Is Wrong with the No-Report Paradigm and How to Fix It, LIT-637, read in NOTE-495: the logic of the no-report paradigm, “The Need for a No-Post-perceptual Cognition Paradigm”, Brascamp et al., “Anticipating an Objection”, Concluding Remarks.
- Block (2007), LIT-646, read in NOTE-497: §§1–7, the methodological puzzle and correlationism. Target article only.
What was actually shown
The puzzle. Block (2007), LIT-646, states the circle: to find the neural basis of experience one must decide whether it includes the machinery of cognitive access, and any evidence of experience seems to come through access. With report, a correlate of a percept is also a correlate of judging it, holding it in working memory and choosing a response. Block (2019), LIT-637, cites that paper as the source of the problem the no-report paradigm was built to solve.
Why removing report is not enough. The no-report paradigm uses reports to calibrate an indicator, such as optokinetic nystagmus for the perceived direction of a rivalrous grating, and then has subjects make no report. Block’s argument is that this removes report and not the thing report expressed. Monkeys spend hours watching gratings with nothing to do but fixate, and “might have some cognitive states – thinking, wondering, questioning, musing, and the like – concerning the grating moving up when it is moving up”. This is not mind-wandering, which would not engender systematic error. It is cognition “systematically aligned with one or another of the rivalrous percepts”. Hence: “Eliminating report is successful in isolating the neural basis of conscious perception only if it eliminates post-perceptual cognitive processing such as thought and judgment about the reportable properties that is systematically correlated with one of the perceptual representations.” The point cuts both ways. Prefrontal decoding of rivalry contents in no-report monkeys does not show prefrontal cortex is part of perception. Block also applies it to the older human no-report studies, “since nothing was done to prevent subjects thinking about their alternating percepts”.
What would isolate it. The target is “a no-differential (between rivalrous percepts)-post-perceptual cognition paradigm”. The word differential is there “to avoid begging the question against views that take conscious perception to be cognitive”. Brascamp et al. made rivalry switches inconspicuous: dots changed direction and coherence every 300 ms, so subjects could not tell a change of dominant eye from the constant background changes (d′ for detecting switches indistinguishable from chance). Density reports and temporal regularities confirmed real rivalry. The switches “were accessible but mostly not accessed”, so no differential thought followed them.
What could have come out otherwise: the argument stands or falls on whether uninstructed subjects form percept-aligned thoughts. That is an empirical premise, and Block argues for it from the situation, not from a measurement.
What this does not say
- It does not say what the neural basis is. Block (2019) says the article’s “main point … is to home in on the methodological issue rather than supporting one side”. The substantive claim is filed separately, as THEORY-098.
- It does not say a general fix exists. “There may be no general solution to this problem, but at least in the case of binocular rivalry a solution may be at hand.” Extending the method beyond rivalry is among Block’s outstanding questions.
- It does not say no-report data are worthless. They remove report and its motor and decision components, and they are what a no-differential-cognition design refines.
- It does not rule on higher-order theories in general. A higher-order state that is post-perceptual is ruled out of the basis of experience by such a design. Block notes that versions where the higher-order state is a simultaneous pointer are not (NOTE-495, Limitations).
How it bears on the crow account
THEORY-100 holds that a neural correlate of conscious report in
crows is carried by the nidopallium caudolaterale (NCL), the functional
analogue of prefrontal cortex. Its own caveat, that a report paradigm
cannot separate access from phenomenal consciousness, is the problem this
account states. Its promote_when asks, for the “conscious” half, for a
no-report or report-independent paradigm in birds. By this account that
would not be enough. A bird watching rivalrous stimuli with nothing to do
may still process the percept cognitively, and NCL, as the prefrontal
analogue, is where that would show. What the crow account needs for its
“conscious” half is a design in which the bird cannot single out the
perceptual change, such as inconspicuous rivalry, with NCL recorded. No
relation is declared. This account does not rival the crow account,
which already concedes the access problem. It does not replace that
account’s reasoning, which is about lamination. And it does not carry its
mechanism further. It bears on the evidence that account names as
promotion.
Connections
- THEORY-102 (Vishne et al.). Its analysed trials needed no report, but each image still had to be judged a non-target. That is differential post-perceptual cognition by design, so its transient prefrontal content at onset is ambiguous between perception and thought about the image. Its sustained ventral temporal code is not ambiguous in this way.
- THEORY-103 answers the same puzzle a different way. It does not try to isolate a correlate. It infers from capacity that experience outruns access.
- Block (1995), LIT-643, supplies the distinction the puzzle turns on: access consciousness is a content poised for reasoning and the rational control of action and speech, and report is its least weighty element. That is why removing report alone was never going to remove access.
Note of 2026-10-29: what holds it back
No result shows the confound operating. The record holds no within-study contrast of conspicuous and inconspicuous rivalry recorded in prefrontal cortex at intracranial sensitivity, and no probe of thought content in a standard no-report paradigm. Block argues from the situation, not from a measurement, that uninstructed subjects form percept-aligned thoughts, and Brascamp et al. (2015), the one design he offers, is held only as he reports it.