The proactive brain: memory for predictions Bar, Moshe
Philosophical transactions - Royal Society. Biological sciences,
05/2009, Letnik:
364, Številka:
1521
Journal Article
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It is proposed that the human brain is proactive in that it continuously generates predictions that anticipate the relevant future. In this proposal, analogies are derived from elementary information ...that is extracted rapidly from the input, to link that input with the representations that exist in memory. Finding an analogical link results in the generation of focused predictions via associative activation of representations that are relevant to this analogy, in the given context. Predictions in complex circumstances, such as social interactions, combine multiple analogies. Such predictions need not be created afresh in new situations, but rather rely on existing scripts in memory, which are the result of real as well as of previously imagined experiences. This cognitive neuroscience framework provides a new hypothesis with which to consider the purpose of memory, and can help explain a variety of phenomena, ranging from recognition to first impressions, and from the brain's 'default mode' to a host of mental disorders.
Rather than passively ‘waiting’ to be activated by sensations, it is proposed that the human brain is continuously busy generating predictions that approximate the relevant future. Building on ...previous work, this proposal posits that rudimentary information is extracted rapidly from the input to derive analogies linking that input with representations in memory. The linked stored representations then activate the associations that are relevant in the specific context, which provides focused predictions. These predictions facilitate perception and cognition by pre-sensitizing relevant representations. Predictions regarding complex information, such as those required in social interactions, integrate multiple analogies. This cognitive neuroscience framework can help explain a variety of phenomena, ranging from recognition to first impressions, and from the brain's ‘default mode’ to a host of mental disorders.
From Objects to Unified Minds Bar, Moshe
Current directions in psychological science,
04/2021, Letnik:
30, Številka:
2
Journal Article
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The involvement of top-down processes in perception and cognition is widely acknowledged by now. In fields of research from predictions to inhibition, and from attentional guidance to affect, a great ...deal has already been charted. Integrating this newer understanding with accumulated findings from the past has made it clear that human experience is determined by a combination of both bottom-up and top-down processes. It has been proposed that the ongoing balance between their relative contribution affects a person’s entire state of mind, an overarching framework that encompasses the breadth of mental activity. According to this proposal, state of mind, in which multiple facets of mind are clumped together functionally and dynamically, orients us to the optimal state for the given circumstances. These ideas are examined here by connecting a broad array of domains in which the balance between top-down and bottom-up processes is apparent. These domains range from object recognition to contextual associations, from pattern of thought to tolerance for uncertainty, and from the default-mode network to mood. From this synthesis emerge numerous hypotheses, implications, and directions for future research in cognitive psychology, psychiatry, and neuroscience.
Highlights • This synthesis of current research characterizes the functional roles of the PHC. • Contextual associative processing is proposed as the core function of this region. • This proposal ...unifies findings for the PHC, creating convergence for future research.
The majority of the research related to visual recognition has so far focused on bottom-up analysis, where the input is processed in a cascade of cortical regions that analyze increasingly complex ...information. Gradually more studies emphasize the role of top-down facilitation in cortical analysis, but it remains something of a mystery how such processing would be initiated. After all, top-down facilitation implies that high-level information is activated earlier than some relevant lower-level information. Building on previous studies, I propose a specific mechanism for the activation of top-down facilitation during visual object recognition. The gist of this hypothesis is that a partially analyzed version of the input image (i.e., a blurred image) is projected rapidly from early visual areas directly to the prefrontal cortex (PFC). This coarse representation activates in the PFC expectations about the most likely interpretations of the input image, which are then back-projected as an “initial guess” to the temporal cortex to be integrated with the bottom-up analysis. The top-down process facilitates recognition by substantially limiting the number of object representations that need to be considered. Furthermore, such a rapid mechanism may provide critical information when a quick response is necessary.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Perception is substantially facilitated by top‐down influences, typically seen as predictions. Here, we outline that the process is competitive in nature, in that sensory input initially activates ...multiple possible interpretations, or perceptual hypotheses, of its causes. This raises the question of how the selection of the correct interpretation from among those multiple hypotheses is achieved. We first review previous findings in support of such a competitive nature of perceptual processing, and then propose which neural regions might provide a platform for rising and using expectations to resolve this competition. Specifically, we propose that it is the rapid extraction and top‐down dissemination of a global context signal from the frontal cortices, particularly the orbitofrontal cortex, that affords the quick and reliable resolution of the initial competition among likely alternatives toward a singular percept.
People constantly make snap judgments about objects encountered in the environment. Such rapid judgments must be based on the physical properties of the targets, but the nature of these properties is ...yet unknown. We hypothesized that sharp transitions in contour might convey a sense of threat, and therefore trigger a negative bias. Our results were consistent with this hypothesis. The type of contour a visual object possesses--whether the contour is sharp angled or curved--has a critical influence on people's attitude toward that object.
Perceptual decisions are biased by recent perceptual history-a phenomenon termed 'serial dependence.' Here, we investigated what aspects of perceptual decisions lead to serial dependence, and ...disambiguated the influences of low-level sensory information, prior choices and motor actions. Participants discriminated whether a brief visual stimulus lay to left/right of the screen center. Following a series of biased 'prior' location discriminations, subsequent 'test' location discriminations were biased toward the prior choices, even when these were reported via different motor actions (using different keys), and when the prior and test stimuli differed in color. By contrast, prior discriminations about an irrelevant stimulus feature (color) did not substantially influence subsequent location discriminations, even though these were reported via the same motor actions. Additionally, when color (not location) was discriminated, a bias in prior stimulus locations no longer influenced subsequent location discriminations. Although low-level stimuli and motor actions did not trigger serial-dependence on their own, similarity of these features across discriminations boosted the effect. These findings suggest that relevance across perceptual decisions is a key factor for serial dependence. Accordingly, serial dependence likely reflects a high-level mechanism by which the brain predicts and interprets new incoming sensory information in accordance with relevant prior choices.
Associative processing is central for human cognition, perception and memory. But while associations often facilitate performance, processing irrelevant associations can interfere with performance, ...for example when learning new information. The aim of this study was to explore whether associative interference is influenced by contextual factors such as resources availability. Experiments 1-3 show that associative interference increases under high cognitive load. This result generalized to both long-term and short-term memory associations, and to both explicitly learned as well as incidentally learned associations in the linguistic and pictorial domains. Experiment 4 further revealed that attention to associative information can delay one's perceptual processing when lacking resources. Taken together, when resources diminish associative interference increases, and additionally, processing novel and ambiguous information is hindered. These findings bare relevance to other domains as well (e.g., social, educational), in which increased load or stress may prompt an undesirable bias towards prior, misleading information.
People see with feeling. We 'gaze', 'behold', 'stare', 'gape' and 'glare'. In this paper, we develop the hypothesis that the brain's ability to see in the present incorporates a representation of the ...affective impact of those visual sensations in the past. This representation makes up part of the brain's prediction of what the visual sensations stand for in the present, including how to act on them in the near future. The affective prediction hypothesis implies that responses signalling an object's salience, relevance or value do not occur as a separate step after the object is identified. Instead, affective responses support vision from the very moment that visual stimulation begins.
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