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Accessibility, and the Mesh between Psychology and Neuroscience
- Forthcoming in Behavioral and Brain Sciences Consciousness
"... How can we disentangle the neural basis of phenomenal consciousness from the neural machinery of the cognitive access that underlies reports of phenomenal consciousness? We can see the problem in stark form if we ask how we could tell whether representations inside a Fodorian module are phenomenally ..."
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How can we disentangle the neural basis of phenomenal consciousness from the neural machinery of the cognitive access that underlies reports of phenomenal consciousness? We can see the problem in stark form if we ask how we could tell whether representations inside a Fodorian module are phenomenally conscious. The methodology would seem straightforward: find the neural natural kinds that are the basis of phenomenal consciousness in clear cases when subjects are completely confident and we have no reason to doubt their authority, and look to see whether those neural natural kinds exist within Fodorian modules. But a puzzle arises: do we include the machinery underlying reportability within the neural natural kinds of the clear cases? If the answer is ‘Yes’, then there can be no phenomenally conscious representations in Fodorian modules. But how can we know if the answer is ‘Yes’? The suggested methodology requires an answer to the question it was supposed to answer! The paper argues for an abstract solution to the problem and exhibits a source of empirical data that is relevant, data that show that in a certain sense phenomenal consciousness overflows cognitive accessibility. I argue that we can find a neural realizer of this overflow if assume that the neural basis of phenomenal consciousness does not include the neural basis of cognitive accessibility and that this assumption is justified (other things being equal) by the explanations it allows.
Interactions between working memory and visual perception: An ERP/EEG study
- Neuroimage
, 2007
"... How do working memory and perception interact with each other? Recent theories of working memory suggest that they are closely linked, and in fact share certain brain mechanisms. We used a sequential motion imitation task in combination with EEG and ERP techniques for a direct, online examination of ..."
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How do working memory and perception interact with each other? Recent theories of working memory suggest that they are closely linked, and in fact share certain brain mechanisms. We used a sequential motion imitation task in combination with EEG and ERP techniques for a direct, online examination of memory load's influence on the processing of visual stimuli. Using a paradigm in which subjects tried to reproduce random motion sequences from memory, we found a systematic decrease in ERP amplitude with each additional motion segment that was viewed and memorized for later imitation. Highfrequency (N20 Hz) oscillatory activity exhibited a similar positiondependent decrease. When trials were sorted according to the accuracy of subsequent imitation, the amplitude of the ERPs during stimulus presentation correlated with behavioral performance: the larger the amplitude, the more accurate the subsequent imitation. These findings imply that visual processing of sequential stimuli is not uniform. Rather, earlier information elicits stronger neural activity. We discuss possible explanations for this observation, among them competition for attention between memory and perception and encoding of serial order by means of differential activation strengths. © 2007 Elsevier Inc. All rights reserved.
From cognitive to neural models of working memory
, 2007
"... Working memory refers to the temporary retention of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be stored for longer periods of time through active maintenance ..."
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Working memory refers to the temporary retention of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be stored for longer periods of time through active maintenance or rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goal-directed behaviour. Empirical studies of working memory using neuroscientific techniques, such as neuronal recordings in monkeys or functional neuroimaging in humans, have advanced our knowledge of the underlying neural mechanisms of working memory. This rich dataset can be reconciled with behavioural findings derived from investigating the cognitive mechanisms underlying working memory. In this paper, I review the progress that has been made towards this effort by illustrating how investigations of the neural mechanisms underlying working memory can be influenced by cognitive models and, in turn, how cognitive models can be shaped and modified by neuroscientific data. One conclusion that arises from this research is that working memory can be viewed as neither a unitary nor a dedicated system. A network of brain regions, including the prefrontal cortex (PFC), is critical for the active maintenance of internal representations that are necessary for goal-directed behaviour. Thus, working memory is not localized to a single brain region but probablyisan emergent property of the functional interactions between the PFC and the restof the brain.
What Happened? Alcohol, Memory Blackouts,
"... Alcohol primarily interferes with the ability to form new long-term memories, leaving intact previously established long-term memories and the ability to keep new information active in memory for brief periods. As the amount of alcohol consumed increases, so does the magnitude of the memory impairme ..."
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Alcohol primarily interferes with the ability to form new long-term memories, leaving intact previously established long-term memories and the ability to keep new information active in memory for brief periods. As the amount of alcohol consumed increases, so does the magnitude of the memory impairments. Large amounts of alcohol, particularly if consumed rapidly, can produce partial (i.e., fragmentary) or complete (i.e., en bloc) blackouts, which are periods of memory loss for events that transpired while a person was drinking. Blackouts are much more common among social drinkers—including college drinkers—than was previously assumed, and have been found to encompass events ranging from conversations to intercourse. Mechanisms underlying alcohol-induced memory impairments include disruption of activity in the hippocampus, a brain region that plays a central role in the formation of new auotbiographical memories. KEY WORDS: alcoholic blackout; memory interference; AOD (alcohol and other drug) intoxication; AODE (alcohol and other drug effects); AODR (alcohol and other drug related) mental disorder; long-term memory; short-term memory; state-dependent memory; BAC level; social AOD use; drug interaction; disease susceptibility; hippocampus; frontal cortex; neuroimaging; long-term potentiation
Functional Interactions between Prefrontal and Visual Association Cortex Contribute to Top-Down Modulation of Visual Processing
- Cerebral Cortex
, 2007
"... Attention-dependent modulation of neural activity in visual association cortex (VAC) is thought to depend on top-down modulatory control signals emanating from the prefrontal cortex (PFC). In a previous functional magnetic resonance imaging study utilizing a working memory task, we demonstrated that ..."
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Attention-dependent modulation of neural activity in visual association cortex (VAC) is thought to depend on top-down modulatory control signals emanating from the prefrontal cortex (PFC). In a previous functional magnetic resonance imaging study utilizing a working memory task, we demonstrated that activity levels in scene-selective VAC (ssVAC) regions can be enhanced above or suppressed below a passive viewing baseline level depending on whether scene stimuli were attended or ignored (Gazzaley, Cooney, McEvoy, et al. 2005). Here, we use functional connectivity analysis to identify possible sources of these modulatory influences by examining how network interactions with VAC are influenced by attentional goals at the time of encoding. Our findings reveal a network of regions that exhibit strong positive correlations with a ssVAC seed during all task conditions, including foci in the left middle frontal gyrus (MFG). This PFC region is more correlated with the VAC seed when scenes were remembered and less correlated when scenes were ignored, relative to passive viewing. Moreover, the strength of MFG--VAC coupling correlates with the magnitude of attentional enhancement and suppression of VAC activity. Although our correlation analyses do not permit assessment of directionality, these findings suggest that PFC biases activity levels in VAC by adjusting the strength of functional coupling in accordance with stimulus relevance.
Cortical dynamics of contextually cued attentive visual learning and search: Spatial and object evidence accumulation
"... saliency map; visual search; scene perception; scene memory; implicit learning; prefrontal cortex; medial temporal lobe How do humans use target-predictive contextual information to facilitate visual search? How are consistently paired scenic objects and positions learned and used to more efficientl ..."
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saliency map; visual search; scene perception; scene memory; implicit learning; prefrontal cortex; medial temporal lobe How do humans use target-predictive contextual information to facilitate visual search? How are consistently paired scenic objects and positions learned and used to more efficiently guide search in familiar scenes? For example, humans can learn that a certain combination of objects may define a context for a kitchen and trigger a more efficient search for a typical object, such as a sink, in that context. The ARTSCENE Search model is developed to illustrate the neural mechanisms of such memory-based context learning and guidance, and to explain challenging behavioral data on positive/negative, spatial/object, and local/distant cueing effects during visual search, as well as related neuroanatomical, neurophysiological, and neuroimaging data. The model proposes how global scene layout at a first glance rapidly forms a hypothesis about the target location. This hypothesis is then incrementally refined as a scene is scanned with saccadic eye movements. The model simulates the interactive dynamics of object and spatial contextual cueing and attention in the cortical What and Where streams starting from early visual areas
Brain mechanisms underlying perceptual causality
, 2004
"... Functional magnetic resonance imaging (fMRI) was used to examine the neural correlates of perceptual causality. Participants were imaged while viewing alternating blocks of causal events in which a ball collides with, and causes movement of another ball, versus non-causal events in which a spatial o ..."
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Functional magnetic resonance imaging (fMRI) was used to examine the neural correlates of perceptual causality. Participants were imaged while viewing alternating blocks of causal events in which a ball collides with, and causes movement of another ball, versus non-causal events in which a spatial or a temporal gap precedes the movement of a second ball. There were significantly higher levels of relative activation in the right middle frontal gyrus and the right inferior parietal lobule for causal relative to non-causal events. Furthermore, when the differential effects of spatial and temporal incontiguities were subtracted from the contiguous stimuli, we observed both common (right prefrontal) and unique (right parietal and right temporal) regions of activation as a function of spatial and temporal processing of contiguity, respectively. Taken together, these data provide a means to help determine how the visual system extracts causality from dynamic visual information in the environment using spatial and temporal cues. D 2004 Elsevier B.V. All rights reserved.
Relational integration
, 2006
"... Analogical reasoning is a complex form of reasoning in which concepts from one situation are mapped onto another situation resulting in new inferences and explanations. More ..."
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Analogical reasoning is a complex form of reasoning in which concepts from one situation are mapped onto another situation resulting in new inferences and explanations. More
Working Memory and Intelligence—Their Correlation and Their Relation: Comment on Ackerman, Beier, and Boyle (2005)
"... On the basis of a meta-analysis of pairwise correlations between working memory tasks and cognitive ..."
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On the basis of a meta-analysis of pairwise correlations between working memory tasks and cognitive

