Metacogniton and Consciousness: from animals to humans


Date: Wednesday 8th (9am - 5pm), June 2011

Venue: Large Conference Room on 3rd Floor of Inamori Center at Kyoto University. 


Summary: Introspection into one's own mental state is a critical ability closely associated with consciousness. One important area of progress over the last decade has been the development of operational measures of metacognitive ability in animals and humans. The talks in this symposium will cover a broad range of recent progresses from metacognition in animals to neural mechanisms in humans. Further, we expect to open a lively, cross-disciplinar discussion on the relevance of metacognition to consciousness.

Organizers: Shintaro Funahashi (Kyoto University, Japan) & Ryota Kanai (University College London)

Contact: Ryota Kanai

Event: This is a satellite event to be held prior to the 15th annual meeting of the association for the scientific study of consciousness. [Click here for link to ASSC15].




9:00-9:20  "Opening Remark & Introduction"
  • Shintaro Funahashi (Kyoto University, Japan)
  9:20-10:00 "Metacognitive approach to phenomenal and access consciousness" Summary
  • Ryoto Kanai (University College London, UK)
In many circumstances, conscious perception fails despite activations of relevant brain regions by subliminal visual presentation. Conceptually, failure to register a stimulus in awareness could be attributed to suppression of early sensory signals (perceptual blindness) and/or failure of attention to register suprathreshold signals (attentional blindness). However, these two types of failure of awareness are difficult to distinguish behaviourally because in both cases, observers would report the absence of conscious percepts.  To distinguish these two types of subjective blindness, we have previously developed a metacognitive framework called subjective discriminability of invisibility, which is derived from the so-called Type 2 signal detection framework (Kanai, Walsh & Tseng, 2010 in Consciousness & Cognition). This new analysis method distinguishes blindness due to signal reduction such as lowering of contrast, backward masking and interocular suppression as perceptual blindness, whereas it classified reduction of visibility due to attentional distraction, attentional blink and enhanced spatial uncertainty as attentional blindness.  Moreover, when we explicitly manipulated decision criterion by changing the likelihood of target present trials, the percentage of target misses increases. When the blindness induced by criterion shift was induced by conservative criterion, the same experimental paradigm shifted from perceptual blindness to attentional blindness. The relevance of these findings for philosophical concepts of phenomenal and access consciousness will be discussed.
10:00-10:40  "Metacognitive Judgments reflect conscious phenomenology  " Summary
  • Hakwan Lau (Columbia Univ, USA)
Subjective reports of conscious awareness are reflected by activity in the prefrontal cortex. Critics of prefrontal theories of consciousness argue that such subjective reports only reflect sensory metacognition, but not the primary aspects of conscious phenomenology. However, ample evidence and conceptual arguments point to the fact that “objective” reports, i.e. reports about stimulus identity, are, if not downright invalid, clearly inferior to subjective (i.e. metacognitive) reports in capturing conscious phenomenology. If we deny the validity of subjective reports, how else can we measure conscious phenomenology directly? Ned Block suggests that perhaps we should give up trying to do so: visual phenomenology may be too rich to be captured by any kind of self-report, and we should instead try to “infer” about its content based on indirect evidence. Here I present data to show that the intuition of phenomenology seemingly overflowing report mechanisms can be explained by studies using subjective (i.e. metacognitive) reports.  Experiments using psychophysics and brain imaging showed that under the lack of attention (as in peripheral vision), metacognitive judgments (such as visibility or confidence ratings) were inflated, such that subjects rated the phenomenology to be undeservedly high relative to the underlying processing capacity. This solves Block’s puzzle of phenomenological overflow, by suggesting that the seemingly rich phenomenology does not actually have an processing capacity basis, and is instead a mere bias. Taken together, I conclude that instead of giving up trying to measure phenomenology directly, all we need to do is to use the right kind of measure – i.e. metacognitive judgments.

---- Break ----

11:00-11:40 "Metamemory in remembering intentions" Summary
  • Satoshi Umeda (Keio University, Departmetn of Psychology, Japan)
In our daily lives, we make plans to do things at particular times in the future. Many investigators have focused on memory of such plans or intentions, which is called prospective memory (PM). The broadly accepted divisions involved in PM consist of a prospective memory component (PMC), a process for remembering to remember, and a retrospective memory component, a process for remembering the content of the intended action. Although both components need to be appropriately processed to realize intentions, PMC is particularly essential since PMC requires spontaneous memory retrieval. In this talk, I will present our neuropsychological and neuroimaging investigations. As a neuropsychological study, I will focus on the question of whether damage to part of the prefrontal cortex affects attenuated performance for PMC. In the study, over seventy participants with traumatic brain injury including focal damage to frontal or temporal lobe areas were administered standard neuropsychological tests and the PM task. The results indicated that the following three areas are highly contributory to PM performance: the right dorsolateral prefrontal cortex; the right ventromedial prefrontal cortex; and the left dorsomedial prefrontal cortex. Comparing differences in neuropsychological test scores showed that orientation scores were significantly higher in the greater PM performance group, suggesting that PMC represents an integrated memory function associated with awareness of current status. I will then highlight the PM training study to investigate the neural mechanism of the two components of PM. The results provide substantial evidence that the two components have independent neural bases. Finally, results from our recent functional MRI study will be provided to support the notion. The overall data contribute to understand the neural substrates and functional characteristics of PM as metamemory.
11:40-12:20 "Awareness of performance: what do we know about our choices" Summary
  • Steve Fleming (University College London, UK)
As scientists interested in studying consciousness, we often elicit subjective reports from subjects about their mental states. These reports can be thought of as decisions with a variety of antecedent processes. For example, some decisions are about properties of the outside world - did I see the target or not? - whereas others are self-referential, such as the confidence I have in my response being correct or incorrect.  I will outline how these different orders of decision-making can be analysed using variants of signal detection theory (Type 1 and Type 2), and discuss the theoretical underpinnings of this approach. Type 1 sensitivity is defined as how well a subject is able to discriminate a property of the task, such as stimulus presence or absence. In contrast, Type 2 (metacognitive) sensitivity is defined as how well subjects can track fluctuations in their own responses. Usually, there is a tied relationship between Type 1 and Type 2 performance - in other words, knowing the answer is correlated with knowing that one knows the answer. Using psychophysics we can break this relationship, and isolate and study a metacognitive component of decision performance. I will present recent behavioural studies that apply Type 2 signal detection analysis to isolate individual differences in metacognitive ability, and discuss aspects of behaviour that may underlie high metacognitive ability. Some of these data were collected in the fMRI scanner, in a paradigm where participants provided metacognitive confidence judgments following discrimination of noisy face/house images. I will present ongoing analysis of these data, aimed at understanding the functional correlates of metacognitive ability. Possible underlying mechanisms (and functions) of metacognition in decision-making will be discussed.

---- Lunch ----

14:00-14:40  "Are birds metacognitive?   " Summary
  • Fujita Kazuo (Kyoto University, Japan)
Studies of avian metacognitive behavior are scarce compared to those of mammals’, nonhuman primates’ in particular. In this talk, we will focus on two aspects of metacognitive behavior in pigeons and bantams. The first will be recognition of the confidence of their immediate decision in perceptual tasks. Pigeons and bantams were trained to peck at a target color among distracter colors on the touch-sensitive monitor. After mastery, a risk-choice phase was appended after visual search; now the visual search led the birds to a choice between a “risk” icon and a “safe” icon. The “risk” icon resulted in a differential reinforcement, in which correct visual search was always reinforced by food whereas incorrect search was punished by a timeout. The “safe” icon nondifferentially resulted in either food or a conditional reward. The probability of choice for the “safe” icon was higher after incorrect visual search than after correct visual search. This differential use of “safe” and “risk” icons generalized to new visual searches with different colors or patterns, and in one pigeon, to a completely different perceptual task, a bar-length classification task. These results suggest that pigeons and bantams may be metacognitive of their immediate perceptual decision. The second will be hint-seeking by pigeons. Pigeons were first trained to form a learning set to make a simultaneous chain of responses. Three icons appeared on the display and pigeons had to peck at all icons in a predetermined sequence. When novel icons appeared, the birds had to find a correct sequence by trial-and-error. However, on some of the trials, there appeared a “hint” icon among the others and pecking at it “taught” the birds the next icon in the sequence by superimposing a flickering frame onto the icon. We gave the subjects a novel set of icons whenever they mastered one sequence. Three of four birds showed a negative correlation between accuracy of the chaining and the proportion of trials in which they requested one or more hints. That is, the pigeons sought for a hint more often when they had fragile knowledge about the sequence than when they had firm knowledge. These results suggest that some birds can be metacognitive in some situations. We will discuss other possible simpler accounts for the results and will propose methods to test those non-metacognitive accounts.
 14:40-15:20 "Metacognition and memory systems in primates: Success and limitations."Summary
  • Robert Hampton (Emory University, USA)
Metacognition is the monitoring and control of cognitive processing. Because metacognition can involve introspection in humans, it can be indicative of explicit, or declarative, cognition and memory. While metacognition is normally inferred from the ability of humans to verbally comment on mental processes, tests of metacognition appropriate for nonhumans have been successfully developed. I will describe the logic of these paradigms and some potential limitations of them. Studies of metacognition may provide a tool that allows us to discriminate between explicit and implicit cognition in nonhumans.

---- Break ----

15:20-16:00 "Prefrontal neuronal activity in monkeys performing a metamemory task" Summary
  • Akio Tanaka (Kyoto University, Japan)
Metamemory refers to the ability to monitor and control one’s own memory. Recent studies indicate that macaque monkeys have cognitive capacities that are functionally analogous to human metamemory. To investigate the neural mechanism of metamemory, we recorded single-neuron activity from the lateral prefrontal cortex (LPFC) of two monkeys performing a modified oculomotor delayed-response (ODR) task. In this task, the monkeys had to remember the location of a visual cue during a several-second delay period, after which they were sometimes forced to take a recognition memory test (forced-test trials) and were sometimes allowed to choose either to take or escape from the test (chosen-test or chosen-escape trials, respectively). Task difficulty was manipulated by varying the number of distractors. During recording sessions, one monkey (Monkey W) consistently showed higher memory performance in the chosen-test trials than in the forced-test trials, which suggests the use of metamnemonic ability. The other monkey (Monkey H) failed to show this behavioral pattern, because of near-ceiling performance even in the most difficult condition. For both monkeys, we observed neurons with spatially selective delay-period activity in the forced-test trials, which had been considered to represent the short-term maintenance of visuospatial information. In Monkey W, the spatial selectivity of these neurons was more similar between the forced-test and chosen-test trials than between the forced-test and chosen-escape trials. This tendency was not observed in Monkey H that did not show behavioral signs of metamemory. These results imply that LPFC neuronal activity in monkeys reflects cognitive processes that are analogous to human explicit memory, a form of memory that is accompanied by metamemory. We propose that the macaque brain might contain neurons that detect the strength of visuospatial information maintained by the LPFC, and that the activity of such neurons might underlie monkeys’ metamemory during ODR performance.
16:00-17:00  "Discussion"