Mack and Rock show evidence that no consciousperception occurs without a prior attentiveact. Subjects already executing attention taskstend to neglect visible elements extraneous tothe attentional task, apparently lacking evenbetter-than-chance ``implicit perception,''except in certain cases where the unattendedstimulus is a meaningful word or has uniquepre-tuned salience similar to that ofmeaningful words. This is highly consistentwith ``enactive'' notions that consciousnessrequires selective attention via emotional subcortical and limbic motivationalactivation as it influences anterior attentionmechanisms. Occipital activation withoutconsciousness suggests that motivated search,enacted through the organism's (...) subcorticalmotivational functions, is needed beforevisual stimulation engenders consciousness.This enactive view – that searching for,rather than receiving or processing input isthe basis of consciousness – was slow ingaining acceptance lacking empirical evidenceof this kind, combined with thestimulus-response assumption that brain eventssubserving perceptual consciousness must resultfrom transformation of perceptual input ratherthan from the organism's self-regulatedactivity as manifested through subcorticalactivity. Implicit perception occurring withword priming is ``paradoxical'' according to Mackand Rock, suggesting late selection forattention after extensive unconsciousprocessing, while most trials involvingnonverbal rather than verbal images mightsuggest earlier selection, sinceunattended objects are unseen, apparently evenimplicitly. This paper argues that anteriorand subcortical motivational mechanisms play animportant role in early selection; posteriormechanisms then unconsciously enhance signals;if data survive early gating andcorticothalamic enhancement, then still further anterior-limbic loops motivatedlyactivate ``image schemas'' resonating withposterior nonconscious processing; at thatpoint, consciousness occurs. (shrink)

Attempts to understand visual attention have produced models based on location, in which attention selects particular regions of space, and models based on other visual attributes . Previous studies of inattentional blindness have contributed to our understanding of attention by suggesting that the detection of an unexpected object depends on the distance of that object from the spatial focus of attention. When the distance of a briefly flashed object from both fixation and the focus of attention is systematically varied, detection (...) appears to have a location-based component. However, the likelihood that people will detect an unexpected event in sustained and dynamic displays may depend on more than just spatial location. We investigated the influence of spatial location on inattentional blindness under precisely controlled, sustained and dynamic conditions. We found that although location-based models cannot fully account for the detection of unexpected objects, spatial location does play a role even when displays are visible for an extended period. (shrink)

Arien Mack and Irvin Rock make the radical claim that there is no conscious perception of the visual world without attention to it.

I have argued in other work that emotion, attentional functions, and executive functions are three interpenetrant global state variables, essentially differential slices of the consciousness pie. This paper will outline the columnar architecture and connectivities of the PAG (periaqueductal gray), its role in organizing prototype states of emotion, and the re-entry of PAG with the extended reticular thalamic activating system (“ERTAS”). At the end we will outline some potential implications of these connectivities for possible functional correlates of PAG networks that (...) are just starting to be mapped. Overall, we will look at many lines of evidence that PAG should be conceptualized as a peri-reticular structure that has a foundational role in emotion, in generating the meaningful organization of behavior by the brain through prototype emotional states, and in allowing the various emotional systems to globally influence and tune both the forebrain and brainstem. Finally, we address implications of these concepts for what is currently understood about consciousness, underlining the need for somewhat more humility within consciousness studies about our current level of understanding of consciousness in the brain, combined with a deeper appreciation of the intrinsic connections between emotion and consciousness. One hopes that more concerted empirical interest in structures underneath the thalamus, combined with a deeper appreciation for the fundamental role that organismic and social value must have in bootstrapping awareness in the developing brain, would begin more widely to influence the fundamental lines of neuroscientific research in both emotion studies and consciousness studies. (shrink)